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Zpacksô Arc Blast Backpack


Our patented 'Flexed Arc' frame creates an air gap against your back for a super comfortable fit. The air space keeps your back cool and also provides a buffer from any lumpy items in your pack. The curve of the frame is adjustable for optimal air flow and fit. No extra padding necessary.

The pack is constructed from tough 2.92 oz/sqyd Dyneema Composite Fabric (DCF). This material is made with ultra high strength Dyneema fiber on the inside, with a protective layer of 50 denier Polyester on the outside. The outer layer gives it even more strength, prevents fraying, and gives it a nice solid color. The material and design can handle loads up to 35 lbs (16 kg).


Weight: 21.0 ounces (595 grams)

Body dimensions: 7" x 12.5" x 30"  (18 cm x 31.8 cm x 76 cm)

Volume: 42L main body, 2.5L each side pocket, 8L center pocket, 55 Liters Total

Frame Height: Short 19" (48.3 cm), Medium 21.5" (54.6 cm), Tall 24" (61 cm)

Load Carrying Features:

Standard Backpack Features:


Torso Height:

Please watch our Backpack Adjustment Video and our Backpack Torso and Belt Sizing Video.

A person's torso height doesn't necessarily correlate to their total height, a taller person can have a shorter torso and vice versa.

To measure your torso height, you will need the help of friend and a string or cloth tape measure. To begin, lower your neck towards your chest. This will cause the C7 vertebra to protrude at the base of your neck. The C7 vertebra marks the top of your torso. Next wrap your hands around your love handles and then use your thumbs to feel for the top of your hipbones; also known as the iliac crest. The bottom point of your torso height measurement will be along your spine at the center point between your thumbs. Using the cloth tape measure, follow the curve of your spine from the C7 vertebra to the center of your spine at the top of your iliac crest. This measurement is your torso height.

The torso height on this pack is adjustable up and down within a range for a perfect fit. If your torso is under 17" (43 cm) consider the Arc Scout which is built for shorter torso heights.

Belt Size:

To measure your belt size use a string or cloth tape measure pulled tight around the spot on your body that you want the belt to ride. Usually this will be near the top of your pelvic bone. The tape measure should be over top of your hiking pants and shirt. Do not rely on your pant size.

A medium belt has a minimum circumference of about 30" (76 cm) including the buckle. Each belt has about 15" (38 cm) of webbing for adjustment.

Choose a belt with a minimum adjustment a couple inches smaller than your measurement so that you can still tighten it down if you lose a little weight on trail.

The belt on this pack is removable and interchangeable. It can be swapped out.


Backpacks are made to order and are currently shipping in about one week. There may also be lightly used gear in our Bargain Bin.

55 Liter Arc Blast Backpack - $325


Belt Size:

Adjustable Torso Height:

Add Options:

Every option below is modular and can be added later.

Shoulder Pouches

These clip to your shoulder straps and are an excellent spot for your camera, GPS, phone, sunglasses, or other items that you want to grab quickly. Mesh on the front of the pouch gives you additional storage for small items like chap stick, keys, etc. They can also be used for .5L water bottles to counter balance a small pack.

These are detachable and can be used on non-Zpacks backpacks as well. They are symmetrical and can be switched left or right. Choose from black Dyneema Composite Fabric or black Gridstop fabric to match your backpack.

Shoulder Pouch Details

Weight: .5 oz  /  14 grams each   Price: $29 each / $50 pair


Belt Pouches

These pouches clip securely to the daisy chain on your padded belt. They have taped seams, a waterproof zipper, and are highly water resistant. Each pouch has about 1 liter of volume and is perfect for maps, snacks, hat and gloves, gadgets, you name it.

These are detachable and can be used on non-Zpacks backpacks as well. They are symmetrical and can be switched left or right. Choose from black DCF or black Gridstop fabric to match your backpack.

Belt Pouch Details

Dimensions: About 6" wide, by 2" deep, by 5" tall.

Weight: .75 oz / 21 grams each  Price: $29 each / $50 per pair


Aquaclip Water Bottle Holder

The Aquaclip allows you to attach a 500ml bottle to your shoulder strap or belt. The bottle can be popped in and out easily on the go.

Aquaclip Details Here

Weight: .43 oz / 12 grams Price: $4.95

Multi-Pack - Four in One Backpack Lid / Chest Pack / Belt Pack

This four-in-one backpack accessory can be attached to the top of your pack as a lid, carried on your chest as a front pack, or worn at your hips as a fanny pack, or carried over your shoulder as a satchel.  About 3.5 liters / 215 cubic inches volume. This will also work on non-Zpacks backpacks as long as there are loops to clip it to.

Multi-Pack Details

Weight: 2.9 ounces - 82 grams   Price: $49


Key Pouch

This pouch is attached to two stick-on-clips. Stick it inside your backpack as a safe place to store your car keys and wallet. We suggest positioning it towards the top of your pack, right behind the shoulder straps where it is easy to get to. Please make sure your backpack fits well before sticking this in. The adhesive bonds well with the inside of our backpack materials.

It is large enough to fit your keys, wallet, passport, or even a large phone like the iPhone 6 Plus as shown. The pouch can easily be unclipped and doubles as a large wallet around town.

The pouch itself weighs .6 ounces (17 grams) and the stick-on clips add about another .1 ounce (3 grams)

Key Pouch Details Here

Pouch Dimensions:  7.5" wide x 5" tall (19 cm x 12.5 cm)

Weight: .6 oz  /  17 grams    Price: $15

Top Side Pockets

These pockets have a loop at each corner to connect them to corresponding loops on the sides of your pack. Since these are not sewn to the pack you can still stand tall items like trekking poles, an umbrella, or a fishing pole behind the pockets. The pockets can be taken off or added later.

The dimensions are roughly 6" wide x 3" deep x 8" tall. They are a good fit for:
-A 1 Liter or smaller pot
-A water filter
-Hat and gloves
-Our rain jacket and pants
-An inflatable sleeping pad

Watch the 'Top Side Pockets' overview video.

Weight: .5 oz / 14 grams each  Price: $25 each / $45 per pair


Ice Axe Loops

A pair of loops are attached at each corner of the pack for securing ice axes. The head of each axe secures through a loop at the bottom, the handle is kept tight at the top with a shock cord band. The loops can all come off when you aren't carrying axes.

Watch the 'Ice Axe Loops' overview video.

Weight: .1 oz  /  3 grams - Both sides of backpack.    Price: $10 / set

Trekking Pole Holders

Adjustable shock cord loops with cord locks are attached to your shoulder strap and to your belt to temporarily hold a trekking pole at either side. These are convenient if you want to quickly stow your poles for climbing,  road walking, or other situations where you don't need your poles temporarily. You can stow them and retrieve them without stopping to remove your pack.

You can easily attach these to any older Zpacks backpacks, or other brand packs. These are attached to both shoulder straps, but can be easily popped off when not needed. Some people also move these up higher on the shoulder strap for securing a water bottle or umbrella.

Watch the 'Trekking Pole Holders' overview video.

Weight: .4 oz / 12 grams - Both sides of backpack.  Price: $10 / set

Roll-Top Closure Straps

All Arc backpacks include a roll top opening by default. Normally the opening is closed by rolling it shut, and clipping a buckle together at the top of the pack.

Roll-top closure straps let you cinch the roll top down to the sides of the pack, rather than simply clipping it together. You can compress the top of the backpack down a little easier, but this is more of a cosmetic option / personal preference. If you add these you still have the freedom to secure the top of the pack the normal way by clipping the top to itself.

The straps are attached to existing loops on the backpack with toggles and they are detachable.

Watch the 'Roll-Top Closure Strap' overview video.

Weight: .5 oz  /  14 grams    Price: $10  / set

V Top Strap

By default there is a single webbing strap going over the top center of the backpack. A single strap works great for lashing on a soft item like a tent or a dry bag to the top of the backpack.

If you need to carry a heavier item, or a hard sided item where the strap can't dig in, you may want a V shaped top strap for more stability. This can be used to carry a bear canister on top of your pack, so long as the canister can squish into your gear as shown. Alternatively a canister can also be carried standing vertically inside the pack.

Attachment points are in place for both the normal top strap, or the V top strap and they are interchangeable. If you add this, the pack is still shipped with the normal top strap too. Detach one or the other depending on your trip's needs.

Watch the 'V Top Strap' overview video.

Weight: .5 oz  /  14 grams    Price: $10

Lumbar Pad

The belt on Arc backpacks already has full-wrap padding behind your back, but this option doubles it with a detachable lumbar pad. The pad slides on or off your existing belt and is held in place by two bands on the back. It is also tied in place at the bottom center so that it can't ride up or down. The Lumbar Pad is made with 3D mesh against your back for more cushion and grip.

If your belt is just a little too large, this reduces the belt circumference by about an inch.

The lumbar pad is about 11.5" wide by 4" tall with 3/8" closed cell foam and 3D mesh padding. (29 cm x 10 xm x 1 cm).

Most people probably won't need this option, and it can be added later if you find you want it in the future. It will also fit all older Zpacks backpacks.

Watch the 'Lumbar Pad' overview video.

Weight: 1.0 oz  /  28 grams    Price: $15

Shoulder Strap Pads

The shoulder straps on Arc backpacks already have 3D mesh on the underside, and most people seem to find them comfortable without any modification.

If you think you need more padding, these pads clip on over your normal straps and can be positioned right where you need them. These can be ordered later if you find that you need them down the road. They will fit most non-Zpacks backpacks as well.

Shoulder Strap Pad Details

Weight: .95 oz  /  27 grams    Price: $20

Roll Top Dry Bags

Up to 6 size medium or medium-plus size roll top bags will fit inside the body of the pack, and up to 3 more can be strapped on to the top and bottom of the pack for long carries. That's alot of capacity! Put your heaviest items (food, water) on the inside of the pack close to your center of gravity, and lightweight items (tent, clothes, pad) on the outside if you run out of internal space. The Large Rectangle Food Bag  is a good fit for this pack.

Roll Top Dry Bags

Spare Belt

The belt on Arc backpacks is removable and interchangeable. This is a useful feature if you lose or gain weight, or if the pack is transferred to a different size person. If the belt wears out before the rest of the pack you could replace it.

The belt is attached directly to a horizontal frame bar. To remove the belt, pull out gently at the center until the frame bar bows enough to pop out of its holster at the left or right. The belt slides off the bar.

To put the new belt on:
  • The pack belt attachment has two pockets (left and right) and two loops towards the middle (left and right).
  • Slide the bar through the right loop on the pack. Then through the back of the belt. Then through the left loop on the pack, and into the left pocket on the pack.
  • Make sure the bar is all the way into the left pocket.
  • Pull out gently on the center of the belt to flex it until the right side of the bar pops into the right pocket on the pack.

Replacing the belt can be a bit tricky and it is not something you would want to do frequently. The spare belt includes a spare frame bar.

Weight: Size medium: 4.0 oz (113 g) DCF material | 4.3 oz (122 g) Gridstop material  Price: $45

DCF Fabric

Belt Size:

Gridstop Fabric

Belt Size:

Shock Cord Lashing

3/32" Shock cord is criss-crossed along the front of the backpack. It can be used to compress the pack, or to strap on items. The shock cord can be detached when not needed. It does get in the way of the center pocket a bit.

Watch the 'Shock Cord Lashing' overview video.

Weight: .5 oz  /  14 grams    Price: $10

Back Story:

The Arc Blast backpack was originally designed in 2012. Prior to that most of our backpacks were "frameless" and relied on a folded or coiled sleeping pad for support. I did my first three thru-hikes (AT, PCT, CDT) with frameless packs very similar to our current Nero backpack. Frameless backpacks are ok for super ultralight loads, but they start to get uncomfortable on the shoulders when they are pushed beyond about 20 lbs (9 kg). On a long hike, heavier food and water loads are inevitable.

Our goal was to create a comfortable pack with a frame without adding any more weight than necessary. A frame keeps the pack rigid making it easier to pack and it also holds its shape when half full. A frame transfers weight to the belt, and feels alot better on your back and shoulders when pushing weight loads into the 20-30 lbs range.

My wife Sheryl and I gave Arc Blast backpacks their first big test on our 2012-2013 Te Araroa thru-hike in New Zealand. This hike was close to 1,900 miles and four months long across all types of terrain the length of New Zealand (Trip report / Gear list).

Our packs held up very well on that trip with minor wear and tear. Since then we have added taped seams and more strategically placed reinforcements for even better longevity. Our packs felt great. They were a big improvement in comfort over the frameless packs we had used in the past. The extra few ounces for the frame was totally worth it, and the cushion and air flow against our backs was appreciated in the warm, wet, humid New Zealand weather.

The original Arc Blast could handle about 30lbs before getting too uncomfortable on the shoulders. In 2015 we updated the frame and belt to push the comfortable load capacity to 35 lbs or more.

Reviews and Customer Testimonials:

Please email us with feedback (good or bad) if you have any!

"The Zpacks Arc Blast is the lightest pack we tested with a frame that can carry up to thirty pound loads. It has good internal storage and we loved that it is practically waterproof. For multi-month hikes where every ounce counts, our thru-hiker testers loved the Arc Blast." The Arc Blast received a 2016 Outdoor Gear Lab "Top Pick"! Read the full review.
"What really sets it apart in the market; itís amazing that a pack weighing so little can carry so well."
Read the Arc Blast Review at HikeitLikeit
CleverHiker Top Pick! - Read the Full Arc Blast Review at

Will Wood gives a Post-Appalachian Trail Thru-hike Video Review of his Arc Blast backpack after 7 months of use.
Adventure Writer Keith "Fozzie" Foskett reports from his 2013 El Camino de Santiago thru-hike with his Arc Blast!
Read his informative Arc Blast review with photos.

Update- Keith has finished his second El Camino de Santiago hike in 2014. "My Arc Blast now has 1900 Miles on the clock and it barely seems worn in."
"On the impressiveness scale, I would put the load carrying abilities of the Zpacks Arc Blast, for loads in the sub 20 range, at exceptional."
Check out the full Arc Bast Review by John Abela (
"The Arc Blast is a deceptively sophisticated backpack that works extremely well in its base configuration but can also be enhanced using add-on accessories." reviews the Arc Blast Backpack
Matt D. reviews his Arc Blast Backpack and his Hexamid Solo-Plus tent and poncho.
"For a thru hiker this pack is worth itís weight in golden Ramen tickets."
Read Dylan T's Arc Blast Review from his 2016 AT thru-hike.
"The Tour Du Mont Blanc was amazing! The Arc Blast did exceptionally well carrying all of my gear and food for 8 days of travel through the French, Italian, and Swiss Alps!" -Ben Smith (
"I just wanted to let you know that I received the pack today. I had extremely high and unfair expectations from the reviews and recommendations I had received, which the Arc Blast has (somehow) more than surpassed! This is my first Zpacks product and I am just blown away by the craftsmanship and functionality. I was expecting some imperfections from a smaller company, but the stitching and the water taped seams are just beautifully done, as is the rest of the pack. On top of all that, I just loaded it up with a lot extra gear and the weight transfer is unbelievable, couldn't really tell the difference between 1 pound and 15 pounds." -Rocky J.
"Got back from my Sequoia adventure with the Arc Blast pack. I was a little apprehensive, I didnít think a one pound pack would handle 35 pounds, expedition canister with food for 9 days included. We weighed them with scales before heading off to trail. At that point I was committed and thought ďoh boyĒÖ. I must say this was the most comfortable pack Iíve ever used. And Iíve used ULA, Six moons, and granite gear stuff. Pleasant surprise!" -Chuck T.
"Thanks for the Arc Blast. We loved it. Best, and lightest of the breed. We used it for four days and three nights through about 32 miles and 6000ft of up and down , rain, sleet, hail, and snow without any fault or discomfort. Also, survived six airplane rides and several mad dashes through the airport with a full load. I'm sure this is nothing compared to what others have done with the pack." -Arlo A.
"I have been using the 60 liter Arc Blast backpack I purchased from you for a couple months now.  I love the pack and I think it's  the most perfect designed and constructed pack to be found anywhere.  I have shown the pack to lots of hikers and recommended it to everyone." -Chuck F.
"Your products have changed my life. I went on the most comfortable backpacking trip of my life last weekend using the Arc Blast, sleeping bag, hood, toothbrush, towels, just about everything you sell, haha. Thanks so much for the wonderful products and your amazing customer service, I will be singing your praises up and down the PCT this summer." -Otto R.
"Alyson & I canít thank you enough for how much we enjoyed the zPacks gear during our recent walk in Spain. Itís not just the light weight Ė the Arc Blast packs are so well designed we just put our gear in and everything was so easy to access when we needed it." -Mark & Alyson
"The backpack was comfortable and survived the harsh environment on the Larapinta Trail in Australia. One of the most comfortable packs I have used. Just large enough for 10 days gear and dehydrated food, three litres of water and SLR camera. Start weight about 17kg." -Peter J.
"Just completed the GR-5 last week in France. The pack was fantastic, easily carrying 10 kgs, completely water resistant through every thunder storm, and unbelievably light. Thanks for a great piece of gear." -Avi. (photo)
"I seem to have (inadvertently) got the JMT southbound record time 4 days, 8 hours, 43 minutes. I used a lot of Zpacks kit on this trip - Arc Blast pack, Hexamid tarp, Zpacks sleeping bag, WPB rain jacket and kilt." -Ralph Burgess
 I am not a super-light hiker but an older guy incrementally dropping weight. I was surprised how comfortable the Arc Blast was. I expected to "give something up" in order to drop weight. Not the case with the Arc Blast! -Doug L.
"The pack is great! 6 days in the Grand Canyon loaded with water, 8 days bushwhacking in the Wind Rivers, 6 days on the AT, all loaded for the duration. Carries far more weight than you rate it for and does so well ... it's a beautiful thing and my favorite of all my packs!" -Bob M.
"The Arc Blast I got some time ago worked great at Philmont this summer, even when hauling up to 50lbs. The Scouts still haven't learned anything about light weight food, so we had plenty of canned goods and gallons of water due to the drought. The pack was uber comfortable, even under such heavy loads. Love your gear!" -Daniel L.
Disclaimer: You probably should not carry 50lbs in this pack, but it is nice to know that you could in extreme circumstances. 30-35lbs is a more reasonable upper limit.
"I just returned from a 10-day trip in the Sawtooth Wilderness in Idaho. The Arc Blast pack was wonderful. It is the best backpack that I have ever owned. Thank you for lightening my load by approximately 2 pounds from last year's trip!" -Todd G.
"I used the Arc Blast on my recent JMT thru hike. The pack performed perfectly! It was super comfortable even with 7 days food in my 12" Bearikade (about 31 lbs total weight) and shows no visible wear and tear. I actually saw several other hikers with the same pack and 100% of the people who had them loved them! I put the Bear can in the middle of the pack to avoid any  potential wear and tear on the bottom, and the weight distribution was great." -Mick P.
"Thank you for quickly sending out my new backpack to Reds Meadows. My old pack was falling apart and I was able to complete the John Muir Trail without interruption. The Arc Blast fits perfectly and was a joy to carry. Many people asked about it and we gave them your website! The Hexamid solo is still working wonderfully after 3700 miles too! Hope you continue to have great success with your business." -Jellybean
"I just finished a JMT thru-hike with a 60L Arc Blast and a Hexamid Duplex, and they both worked fantastically. The pack held my BearVault 500 with a peak weight of about 25 lbs without problem, and it still looks in good shape!" -Austin L.
"This year I was trekking in the French Alps and found Arc Blast just fantastic! It sits very well on your body, I could easily adjust the frame to regulate the distance between the pack and my back, size and placement of the side pockets is very good, my drink bottles and small snacks were very safe there. I felt like backpack was very well 'united' with my body. We were trekking through some difficult terrain and it was very comfortable, I'm really impressed. I did get some tiny scuffs on the bottom from resting it on sharp rocks, but other than that it is great. I'm so glad my friend told me of your website." -Ewa K.
"Just wanted to send a quick thanks for my Arc Blast! I have been absolutely loving it and giving it a workout. Best pack I have ever owned. Here's a view of the Chinese Wall in The Bob Marshall Wilderness." -Will F.
"I received my 52L Arc Blast a couple of weeks ago and am more than impressed with the quality, workmanship, and the overall comfort! Iíve never hiked 20 mile days in a more comfortable pack! I donít even feel like taking it off during breaks on the trail! Its INSANE!!! I tell all my hiking partners and friends about you guys!" -Rock S.
Fellbound discusses the merits of his Arc Blast Backpack and his Challenger Rain Jacket in this Arc Blast Review.
"My pack rocks. I really like the lumbar pad Ė just that extra bit of comfort and also stands it off my back a tiny bit more. Plenty of ventilation, but still firmly in place. Carries loads from 15 to 25 lbs with ease. Very, very nice; and gets lots of comments on the trail." -David A.
"Thanks a lot Joe. I just took the Arc Blast out on a 5 day section hike from Deep Gap NC to Fontana Dam. It was awesome! I had a fairly low pack weight but it felt like I was not using a pack at all. I also tried out my new Duplex tent, 30F Down bag, and Challenger rain jacket. They all performed really well. I had a lot of interest from AT thru hikers I met on the trail. I took the opportunity to sing the praises of your great equipment." -Michael H.
"Our May 2015 Gila Wilderness trip became an epic. We bushwhacked through extreme terrain, climbed canyon walls with belays down obstacles, and swam through canyon pools that had no other way of progress. We each had Arc Blast packs, and your tents and sleeping bags. The weather was cold and rainy with snow above 9,000 feet. We bushwhacked through some of the most difficult terrain I have ever challenged. Both ArcBlast packs took a beating. We scrambled through and over rocks as well as through heavy brush and stickers. We even swam our ArcBlast packs through a 40 foot canyon pool. John must have been more careful than I because he needed no trail repair. He did have some fabric injury but nothing serious. My side pockets developed several snags and small holes that I repaired on the trail with Cuban Tape. Otherwise I have found no other damage. The ArcBlast pack is comfortable beyond my expectations. We were each carrying about 22 pounds and I found that I hardly noticed the pack on my back. I have used many packs and none have ever accomplished this. After swimming through a canyon pool 40 feet pushing my pack ahead of me (they do float fully loaded) I might of had a tablespoon of water inside the pack." -Jay B.
ďI bought an Arc pack from you a month ago at the ADZPCTO-- it is PERFECT and I enjoy perfect things. Now I would like to buy a Duplex tent and the titanium stakes to go with it.Ē -Tom L.
"I love your pack that I bought way back in 2012! I enjoy is so much I've finally posted a long overdue Owners Review on I hope you all find the review as enjoyable as I find the pack!" -Steven K.
"My pack performed great! Here's a picture of a happy hiker taken on side of Sonora Peak on the PCT. I had gear & water for both of us & it carried really well. As I hiked with my new pack I was really impressed by all the care and thought and inventiveness that you put into creating it. When it arrived though it looked delicate ó all that exposed carbon ó long time since I'd had an external frame pack. But it performed so well and I got used to seeing the frame and was reminded how much nicer the carry is on external frame packs. It's really well done. I'm glad for all the features I chose. Turned out just right. Oh and that grey color is particularly beautiful. Nicer in person than on the website." - Aife M.
"The Arc Blast backpack was wonderfully comfortable (and of course light) even with a 7.5-day carry of food. I especially appreciated how modular the pack was. Being able to take off the belt pockets was particularly useful when scrambling and rock climbing during summits of random fun mountains (Banner Peak, Warlow, Huxley, and John Muir Rock)! I found the pack to be impressively water proof during persistent rains." -Nathaniel C.
"I wanted you to know that your Arc Blast pack performed beautifully during a six day hike on the AT in New Hampshire. It is super light and very comfortable. It has been terribly wet up here so the trails were awful, but the slogging was made easier with your pack." -Rand W.
"I took my new Arc Blast out for a four hour test up Mount Tamalpais this morning and it performed flawlessly. It has just enough space for the Bearikade Expedition as you said it would. Thank you for the superbly designed Arc Blast and your prompt reply." -Jon O.
"I just finished hiking the PCT from Campo to Cascade Locks and couldnít have done it without my Arc Blast, Zpacks sleeping bag, and Duplex tent. I have never had a backpack fit so comfortably on my back or carry loads with such ease. The quality of your products and customer service of your company is unparalleled." -Austin J.
"We have just completed our 515 mile hike across Washington on the PCT. Having now put our new Duplex tent and my Arc Blast pack through their paces, I wanted to send you some product feedback. I admit I was very skeptical about ordering this minimal pack, but I soon came to know it was a perfect choice for me. I love it! It is so comfortable, easy to use, and durable, not to mention attractive. Barely a day went by without another hiker noticing and asking about my pack. Many thought I was a Zpacks Ambassador because of my glowing and hearty endorsement of the pack!" -Heidi P.
"My friend's bag arrived. Gorgeous green. Your colors are much more beautiful than they appear on the website. I was worried flying recently since the bag frame measured about 23" and the carry on restrictions are 22", but I can tell you the bag slides into overhead bin (like a roll bag would) with an inch or two to spare. Yay. I use my 4 in 1 multi-pack all the time now and it is the best. Comfortable. You have put so much good thought into these bags and I'm feeling quite lucky as the recipient" -Aife M.
(Editor's note- Airplane overhead bins are curved in the shape of the hull of the airplane. You get a few extra inches of depth at the bottom of the bin. I have flown a dozen times on different airlines with no issue with a medium frame.)
"Is this what you had in mind with you designed the Arc blast? :). Arc Blast backpack shown fully loaded. The bear can is mine but the two extra sleeping bags were to help some other folks. The pack works great." Doug L.
"You're just too good at improving things, Joe. A never ending source of temptation. Thanks for everything. Hiking has brought me so much happiness and spiritual growth -- and your brand of trail magic had been essential in making it possible for this well worn 67 year old body." -River M.
"This pack have seen a lot of use in the last year and a half since I've owned it and I really have enjoyed carrying it. This Arc Blast has been a bombproof pack. Thanks for your design and your production quality." -John K.
"I recently finished my 2015 AT thru hike using your 60L Arc Blast. An absolutely amazing pack. I abused it daily and it held up. A few holes in the mesh and some abrasions in one side pocket (probably from numerous falls and slides in the Whites) but was still functional. Best pack I've ever used and it just might make another thru. Thanks for great service and an awesome pack." -Don W.
"My Arc Blast Pack is TERRIFIC. Needed one of these years ago. I have used this every week since I bought it last year." -Annie W.
"This year my family and I hiked the Appalachian Trail. Although other families have done it in the past, we were the only family in 2015 to complete the entire thing with all members (Father, mother, and 5 kids) hiking every mile. All but our two smallest sons did it with Zpacks backpacks! Our family absolutely loves your products!" -Brent H.
"I received your pack just in time for my first real backpacking trip on the Outer Mountain Loop in Big Bend, Texas. I'm 47, in pretty good shape and to date that was the most grueling thing I've ever done. That was echoed by others in my group who are career military guys (a few of which are triathletes and seasoned backpackers). In the desert stretch it was close to 100* with lots of elevation change. One of my buddies who runs 30 miles/week had a heat stroke & I feel like we barely got him out. Because you kept my request date in mind and got my pack out in time it absolutely made the difference. The pack was light enough I was able to carry that extra liter that I gave to him and the dual straps allowed me to carry half his heavy gear right on top of mine. We managed to get him out of that last 7 miles and carried back into the basin. Of course I felt the weight but I NEVER even felt your pack on my back while others were complaining about their hips and shoulders. I make and build a lot of stuff my self, and I had tried 4 other lightweight packs before yours but you have made such a well designed pack I honestly don't know how it could be improved. I just wanted to thank you for such an awesome product, for your customer service and for making the difference in helping me get to the finish line." -Jerry B.
"I'm really enjoying testing the Arc Blast (for Trail Runner Mag Online). It's probably the best designed pack I've ever used - fastpacking or backpacking." -Ben L.
"I used the Arc Blast on my 2015 AT thru-hike. The pack was DONE at the end of the 2200 miles. That is what I expected and was extremely happy with the pack. I plan on doing the PCT next year and plan to get another Arc Blast or the Arc Haul for more durability." -Sol E.
"I used the backpack for the first time a couple weekends ago and put in a solid 36 miles. I have to say I absolutely LOVE the pack. Even with all the attachments and extras I came in 10 oz lighter than my previous lightweight backpack. BUT, yours was so much more versatile, adjustable, comfortable. The pouches were bigger, the belt had dual adjustments to keep it snug to my hips but not squeeze my stomach. I played around with creating a bow in the frame to keep the pack away from my back which was amazing in the 90 degree weather (with 90% humidity). I am very very happy with it. It was a huge increase in price for me, but well worth it and you can see the level of detail, craftsmanship and knowledge that went into the design." -Zack F.
"Back from trekking the JMT. Managed to complete the full trail in 8 days thanks in large part to my Z-Packs-based ultra light kit, including the Arc Blast, Altaplex and 20 degree sleeping bag. All the gear held up great. Photo attached from Forester Pass." -Kevin B.
"Thought youíd like this picture of three Z-packs in the Grand Canyon. Was backpacking with my friend and ran into this guy with his Z-hat and pack. Instant bonding. Seriously! Best gear Iíve used. Have the backpack and tent. Love it! What a difference it makes with light comfy gear!" -Anna S.
"I received my pack yesterday and I wanted to tell you how impressed I am with the '2017' improvements. Moving to the pockets for the stay holders is huge and the switch from cord to webbing straps on the mesh back panel is even bigger. The more flexible stays makes the adjustment easier, and now I donít dread tightening and loosening the stays whenever it is handy. I found myself loosening the stay tension in camp if I wanted to put the pack under my feet at night and whenever I put it in a trunk for the ride to the trailhead. Seriously great improvements." -Wayne V.
"I hang my external hydration bladder closest to my back from the haul loop, in the curve between my shoulder strap attachments and it works great. Here is a photo of my water bladder. Try a carabiner instead of the cord. In the morning the water is ice cold on my back but it feels good. What I love about your packs are they are wide and skinny so the weight is closer to my back yet I have airflow. You have the best frame and hipbelt, and lots of little features carefully thought by someone who is building pack he wants to carry. Again thank you.
"I recently used my Zpacks backpack for the first time on a short trip and I loved it. I had no soreness after a day of hiking, and it is so light! So thank you for your great product. Also, after my extolling the virtues of your products, two of my fellow hikers plan to purchase packs from you. Iím preparing for a solo hike of the John Muir Trail and I have to prepare carefully, as I am a 110 lb. older woman." -Sarah P.
"Iím emailing to report that my Zpacks Arc Blast 55L is no longer just a ďGreat Pack -- So Far.Ē As of August 3, 2017 it is now a "Great Pack -- All the Way to Katahdin!" I had a couple of worn spots on the straps, some wear where the belt attaches to the frame, and a hole in my shoulder pouch mesh. Other than that I find it amazing that the DCF material sustained no damage despite numerous encounters with rocks and trees. Thanks for a great pack and great customer service!" -Greg S.
"My Arc Blast has replaced my 36 y/o Kelty external frame pack. I recently completed an 11 day solo trek of Peru's Cordillera Huayhuash. The pack left me with a big smile. My basic pack weight plus food was at 34 pounds. The pack carried this well. I hate a sweaty back and the Arc Blast kept me dry and carried my load well. On numerous occasions Iíd stop for a break and did not even bother to remove the pack, it felt that good." -Walt W.
"I have only owned my Arc Blast for 3 years, but I am extremely impressed with it. After having owned numerous (ultra)lightweight backpacks before, it is so much more comfortable, does a great job at transferring weight, is sturdy yet very light. Obviously, no news for you. As somewhat of a gear junkie I have owned a lot of gear, with mixed feelings, often selling it again after trying it out. The Arc Blast is the best backpack for my ultralight ventures and big enough to carry my packrafting or bear can as well. I absolutely love it! Keep up the good work. Here is a photo of my Arc Blast and I at the Harding Icefield in Alaska." -Rob D.
"I have only had a couple of short trips out with my recently acquired Arc Blast and Duplex, but I wanted to share my initial thoughts, which are short and simple: they are awesome! Are they kind of expensive? Yeah, but they are just fantastic! I am in love with them. I wish I got them sooner. Thank you for the awesome products which Iím sure are going to help make my backpacking trips in the future even better and more enjoyable!" -Sam S.
"Hey guys! I just wanted to give you guys a huge thumbs up towards the Arc Blast. I have had it for a few months now and it is quite a spectacular pack. It has been a lot of fun continuing to make the transition into ultralight backpacking and I look forward to using the pack on my Appalachian trail through hike starting this May." -Jason P.
I love my original 2013 Arc Blast. In my 7000+ km, all in Europe, my pack was universally admired, or at least noted for its oddness. Only met one other with it- who loved his pack as much as I love mine. My pack is getting quite frayed now. I think I will take the plunge and get a new updated one." -Connie K.
Our Flexed Arc Frame is is covered by US Patent No. 9,060,590

Our torso height adjustment mechanism is is covered by US Patent No. 9,848,687