ULA Circuit and ULA Ultra Circuit Backpack Long-Term Review
Reliable, durable, and comfortable backpacking pack
April 3rd, 2025
Home > Gear Reviews > Backpacking
Updated with testing notes on the Ultra Circuit and comparison on design, material, and performance in the field, and details on similar packs to consider
Our Verdict
The ULA Circuit is a workhorse of a backpacking backpack that can take you from Mexico to Canada, or from the parking lot to the lake campsite five miles ahead. It can handle pretty much anything most lightweight backpackers will throw at it.
Reliable, durable, and comfortable, I would buy this pack again — although it is so durable I don’t know when it would need to actually be replaced. However, I did replace it in 2024 just to try out the new version, now available in Ultra fabric called the Ultra Circuit.
In this guide, we’ll explore the features and share what I've learned over 5,000 miles of backpacking with this pack in both the Robic and Ultra Circuit versions, so you can determine if the ULA Circuit is the right backpack for your backpacking trips.
If you are looking for an internal frame pack and want to be ultralight while still having the flexibility to carry bigger water loads and food hauls, this is a great pack for you–whether you go with the original Robic version or the Ultra version.
The roll-top collar makes the Circuit a Goldilocks pack — not too big and not too small for any adventure.
Still, the simple design might seem difficult to get used to at first if you are transitioning from a pack with separate organizational pockets and a brain. It is also easy to attach anything extra that you might need on this pack: shoulder strap pockets, a Kula cloth, or chips on the shock cord.
I have carried up to 9 liters of water, and on other occasions, I have carried 10 days of food, and this pack was able to comfortably carry both these loads. When I carried it on a thru-hike of the Tahoe Rim Trail with my dog, I had to carry water during the dry sections for both of us, up to nine liters for short sections.
On the Pacific Crest Trail, I had sections where I carried 10 days of food between resupplies. The pack was fully loaded to the very top on the first day of those longer stretches. Plus, it carried my bear can.
The ULA Circuit is also in our Best Lightweight Backpacking Backpacks guide.
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Specs
Sizes: Torso sizing starts at 15” for a small and goes up to 24” for XL, hip belt sizing starts at 26” for XS and goes up to 47” plus for XXL
Weight: 37.3 oz (Robic), 33.8 oz (Ultra)
Capacity: 68 L
Max Recommended Weight: 35 lbs
Main Body Pockets: One large pocket, 39.3 cubic L with a roll down top
Internal Stash Pocket: Not included
Water Bottle Pockets: Two side pockets 6.6 L, each can hold either two 1 L Smartwater bottles or a 1.5 L with a 0.75 liter smartwater bottle to maximize water capacity
Hip Belt Pockets: Two 1.6 L, each perfectly fit a cell phone, Garmin InReach, sunscreen, hand sanitizer, and of course SNACKS
Extension Collar: 8.19 L allows for overflow of food and gear for longer stretches
Mesh Pocket: 6.6 L and allows for stuffing a tent or wet rain gear away from dry clean gear inside
Shoulder Strap Pockets: Add ons available from ULA or from other brands
Suspension: Yes, internal suspension hoop
Load Lifters: Yes
Compression System: Roll top with single strap in addition to side compression straps
Roll Top Closure: Buckles and strap
Material: 400 Robic and now a new Ultra Fabric
Gender: Non-gendered pack, shoulder straps have J or S shape options
Front Shock Cord: Yes
Ice Axe/Trekking Pole Attachment Point: Yes
Bear Canister Capacity: Can carry up to a BV500 vertically inside or horizontally on top
Comparison table
| BACKPACKING BACKPACK | MSRP | VOLUME (L) | MATERIALS | WEIGHT (LBS) | MAX LOAD (LBS) |
|---|---|---|---|---|---|
| ULA Circuit | $300 | 68 | ULA 400 Robic | 2.3 | 35 |
| ULA Circuit Ultra | $380 | 68 | Challenge ULTRA™ | 2.1 | 35 |
| ULA Catalyst | $320 | 75 | ULA 400 Robic | 2.8 | 40 |
| Gossamer Gear Mariposa | $315 | 60 | 100 & 200 denier Robic high-tensil strength nylon | 2.0 | 35 |
| Hyperlite Mountain Gear 55L Southwest | $379 | 50 | White: DCH50 (Main Body) & DCH150 (Bottom) Black: DCH150 (Main Body & Bottom) | White: 1.9, Black: 2 | 40 |
Best For
The ULA Circuit is suited for anything from a casual overnight backpacking trip to thru-hiking a Triple Crown trail. This pack is adaptable and can be scaled up or down depending on your needs for your trip. I have carried this pack on a simple overnight backpacking trip and a full thru-hike of the PCT. It is best for someone who has gotten a total pack weight down to under 30 pounds and who wants to have the support of an internal frame pack.
Updates in the newest versions
The author (left) backpacking in the new Ultra Circuit.
The Circuit is a classic backpack that has been around for nearly a decade. But for those who think this pack hasn't seen any updates since then, ULA is always innovating. Here are some of the newer changes compared to older models of this backpack:
For those who prefer the water resistance and durability of Ultra fabric, a model of the Circuit is available in Ultra. We've tested both and compare the two fabrics below.
For both Ultra and Robic versions, the regular mesh on the front pocket has been replaced with an UltraStretch Mesh for added abrasion resistance and durability
Combination ice axe/trekking pole loops are now a standard feature on both models
Low profile loops are added to the top and bottom of these packs to accommodate removable top or bottom straps to lash gear to your pack on both models
How We Tested
I have carried this pack over 5,000 miles and counting. I actually purchased this pack a couple hundred miles into my 2018 Northbound PCT thru-hike, replacing my ULA Catalyst (which ended up being too big for my needs) with the ULA Circuit. I carried the Circuit all the way to Canada in 2019. Then, I carried that same Circuit on a thru-hike of the PCT Southbound the next year. I also used this pack for my recent Tahoe Rim Trail (TRT) thru hike and many other smaller hikes in between.
I have worn it through every type of weather, rain, snow, heat, and wind. I used this pack to carry my own gear and I have also used it to carry gear for my dog. I have taken this on snowshoe trips and day hikes, peak bagging — there aren’t many outdoor adventures where I don't choose to use this pack.
I also use the ULA Circuit on smaller day hikes. To reduce the volume, I kept most of the gear in the main body pocket and rolled the straps down, using all the compression straps to keep it nice and tight.
What We Like
The Circuit is super versatile — the roll top closure allows for it to be scaled up or down depending on what gear you are carrying and how much food you are eating.
The main pocket can hold a BV500 bear canister vertically with gear stuffed around it.
The padded back panel means that you don’t have to be worried about how you load your pack, you won’t feel things poking you.
The large mesh pocket on the back is super stretchy and can hold a tent, rain gear and trash, keeping your gear on the inside cleaner and drier.
The shock cord on the back secures socks you want to hang out to dry and allows bags of chips to be easily accessible (without getting crunched inside your pack).
The top strap can easily hold a foam sleeping pad or rolled up tent.
Plenty of opportunities to customize this pack for your needs.
What Could Be Better
I would love to see a built-in phone pocket at the shoulder straps. You can still easily attach third-party shoulder strap pockets, though.
The hip belt pockets are harder to use for quick access than we've seen on other packs. The zipper placement isn’t ideal for quick access to gear.
I would love to see some sort of slip pocket add-on for a phone on the outside of the hip belt pockets or at the shoulder straps.
Features
Front Pocket
The front mesh pocket is super stretchy and durable. It is great for keeping a toileting kit separate from other “clean” gear. I was also able to shove my Zpacks Duplex tent (see our in-depth review here) into the mesh pocket, along with rain gear and, of course, TRASH. I love being able to separate gross and stinky gear from my cleaner gear that is inside the main body compartment.
Side Pockets
There are two side pockets and each can easily hold two 1 L Smartwater bottles (4 liters total). You can shove a few bits of extra gear like a rolled up Sawyer Squeeze bag in the side pocket or trekking poles, or a sun umbrella. There were times I pushed the limits with a 1.5 L bottle and a 0.75 L bottle, but that made it harder to get the bottles out for drinking while hiking.
Hip Belt Pockets
The hip belt pockets are a decent size, perfect for snacks like bars and gummies. I usually stash a Garmin inReach and sunscreen in there as well for easy access.
Shoulder Strap Options
Two options are either a J or S-shaped strap depending on body size/type. The S shape is more comfortable for individuals with larger chests or bigger builds. I ordered the S straps, and found the shape to be very comfortable. The straps also have webbing and D rings to attach pockets or other accessories.
Although ULA doesn't specifically market the S-straps for women or femme bodies, many women think that it is more comfortable. For more recommendations on fit, see our Best Women's Hiking and Backpacking packs guides.
Hydration Sleeve and Hydration Ports
The hydration ports are located at top of the pack on the left and right sides; these ports have been eliminated in the Ultra versions to keep the packs more waterproof. The hydration sleeve is available as an add on. However when I used a bladder in this pack I preferred to lay it towards the top of my pack horizontally so that as I drank the water, my pack height got shorter.
I found it difficult to slide the bladder into the sleeve multiple times a day. That being said, if you are using this pack for day hikes, the sleeve is an excellent option to keep your water separated and organized.
Trekking Pole and Ice Axe Attachment Loop
These loops are now standard on the Circuit packs and offer a place to attach your gear easily.
Materials
The 400 Robic material is very durable and comes in several color choices. The mesh pocket is stretchy and allows for a decent amount of extra storage in the pack.
Ultra fabric is a newer fabric on the market that is stronger, lighter, waterproof and more durable than traditional Robic. The Ultra version uses the same stretchy mesh pocket material as found in the Robic version.
Compression System
There are two side straps that can be tightened down to compress the load of this pack.here are also two straps that come off the roll top, allowing it to compress down as well. You can also use the side straps across the front to compress it more.
Padded Back Panel
The back panel is padded with a mesh material. I usually make sure to pack my bag with something like my folded inflatable sleeping pad against the back for extra support just to make it even more comfortable. Check out our favorite sleeping pads in our Best Sleeping Pads for Backpacking guide.
Sternum Strap
The adjustable sternum strap can be raised or lowered. I appreciate this option as someone who likes to vary the position of the support. There is a magnetic strap version available as an add on which has the benefit of one handed operation while hiking.
Roll Top Closure
The roll top closure is really where the magic of this bag comes to light. You can overfill the roll top and barely close it if you have a super long segment of hiking, and likewise you can roll it super tight and small if you are at the end of a segment and have less food and supplies in your bag.
Durability
The 400 Robic fabric is very durable. I have been surprised at how well this pack has held up over several years of hard use. I have sent it in for repairs to replace straps that were fraying, but the pack fabric itself has held up extremely well. The fabric has some fading from the sun —you can see where it has faded when you look at the roll top and the part that is folded inside is darker than the rest of the pack.
Comfort
An adjustable suspension pack allows for customization to carry the load in different ways. I switch back and forth between the weight on my hips and shoulders depending on how I am feeling and if I am hiking up or down hill.
Made in USA
These packs are still made in the USA and you can send it in for repairs to be fixed too.
Warranty and Repair
ULA offers excellent repair options. I have sent my pack in twice to be repaired and ULA has always done an excellent job of taking care of my pack and getting it back to me in perfect trail shape. I don’t have to worry about wearing down this pack because I know I can get anything fixed pretty easily. I usually email or call and they quote me a price on the repair.
The biggest failure points for me have been the male parts of the buckles breaking off and the webbing straps fraying. I know of a few hikers who had a warranty issue on trail and ULA provided them with excellent customer service and got them back to hiking with a replacement pack. You can read more about ULA's repair and tune-up program in story.
Design differences between Robic and Ultra Version
We tested both the Robic and Ultra Circuit. The Ultra Circuit is made with Challenge Ultra fabric (aka, Ultra), which is waterproof and made of stronger, lighter materials.
ULA writes that Ultra is "15x stronger than steel by weight, twice as abrasion resistant as standard 420D nylon, and waterproof to 200 psi." They also say "Ultra fabric lasts longer, absorbs 80% less moisture, and has better UV resistance and color retention than traditional laminated nylon." Ultra is made from 100% recycled polyester. They write, "Every yard contains over 20 plastic bottles and saves over one pound of carbon emissions compared to standard pack fabric."
The Ultra Version weighs about 4 oz less than the Robic version for a similar volume pack with similar max load. It is only available in gray.
Another main difference in design is it has no water hose port.
For details on how the two perform on trail over extended time, see our Performance in the Field section.
Materials: What is Ultra? What is Robic?
Ultra fabric is a newer fabric on the market that is stronger, lighter, waterproof and more durable than traditional Robic.
Ultra is similar to the popular DCF fabric used in tents and other packs with more durability fixing the issue many have with DCF and Xpac material packs where holes develop in the fabric in heavy wear areas. For now Ultra Fabric is the happy medium between crunchy plasticky DCF and super flexible and not waterproof Robic materials.
The Ultra packs come with a significant price increase and may not be the right choice for everyone. This article in Backpacker argues against Ultra and favors the tried and true Robic. I've tested both of them side by side and you can read about my experience and comparison in the Performance in the Field section.
Performance in the Field: Robic vs. Ultra Version
For this story, I tested both the Robic and Ultra versions of the ULA Circuit. Here are my notes from the performance in the field of the two packs.
Waterproofness/Seam Taping
Ultra fabric promises to be waterproof to 200 psi, which should cover most rain storms. This can eliminate the need for a liner in the pack. Most of our testers still prefer to double up and use a trash bag or poly pack liner when they know they might have a lot of water crossings or heavy rainstorms.
We do appreciate that the waterproof fabric doesn't absorb water making it lighter to carry in wet weather and easier to shake off before getting into a tent at night.
Fabric stiffness
The Ultra Fabric is more static, meaning there is less stretch to it compared to the older Robic fabric. I am someone who throws my sleeping quilt and clothing in the bottom of my bag and fills all the space so nothing is rattling around. The Ultra Fabric is more stiff and has less stretch to it.
The Ultra packs are stiffer and do require a little more planning to get them packed nicely compared to the Robic where you have a more wiggle room with the slight stretch. I find that I have to be a little more careful about spreading out my soft items and burying my stove and things in the center.
Noise
The Ultra Fabric is similar to the XPac fabric in terms of noise. My hiking partner is very sensitive to noise and the crinkling of the Ultra Fabric is noticeable in camp at night. The Robic is softer fabric in comparison and reminds me of well worn denim with very little noise.
Delamination
There are some reports from Ultra pack users online about the fabric delaminating over time. We have not had this experience with ours yet. Ultra is supposed to be more resistant to delamination compared to the Robic fabric.
Our Robic tester had some delamination on the collar of the Circuit after about 3,000 miles but the rest of the pack remains in great shape and is still in use.
The Ultra version was only released a year ago and so far, the Ultra fabric is not showing any signs of sun fading or wear after a season of backpacking trips.
Color options and fading
Robic fabric comes in a rainbow of color options and if that is important to you, it is absolutely the way to go. Depending on what color you choose, your pack may show lots of dirt and fade in the sun.
In our experience, the Robic fades in the areas that get the most sun exposure while hiking and wear, just like a favorite pair of jeans.
As of now Ultra only comes in Gray, which is a nice option for hiding dirt while backpacking. After a year, mine has no signs of wear or dirt even after hiking in hot, desert areas. My gray pack also has not faded at all from its original color.
Customization
ULA packs are made in the USA in Logan, Utah. If there is a custom feature that you are looking for, you just have to send them an email for a custom Circuit and they will come back with a price estimate for you. I have emailed them with little requests and they have always been extremely helpful. There's even a spot on their website just for requesting custom packs, so you can play around with options.
Adaptability
Many parts of the pack are removable, from stash pockets and hip belts to hand loops. My partner has this pack and removed the suspension hoop and metal stay to make it frameless. He also removed the hip belt to make it lighter, — just another way this pack can be altered to fit your needs.
Many items are available for add on such as:
Add-on features that allow you to strap gear to the outside of the pack either on top or bottom. The top strap works to help strap a standard bear canister to the top of the pack
Pack covers keep your pack dry in a rainstorm. Learn more in our section on how to pack your pack to keep your gear dry.
These pockets attach to the shoulder straps and can easily hold a cell phone or garmin device, snacks, sunscreen and more.
The ULA Flow is a mesh pocket that attaches to the shoulder straps and can hold up to a 1 L Smartwater bottle.
There is an additional attachment with a mesh pocket designed to hold a can of bear spray, making sure it is always ready to be used. This is significantly lighter than the bear spray pockets that come with most cans of bear spray.
Small extra pocket to hold cards, cash, or maps/permit. Available as an add on to hold your keys or cards and permits. The stash pocket hooks into internal loops inside the back.
The internal hydration sleeve holds your bladder so it stays organized in your pack.
Hand loops give your hands a place to rest. This is handy (haha) if you don’t use trekking poles (one of the benefits of poles is they can help reduce swelling in your hands). The hand loops on the pack can also keep hiker hands from swelling as they walk. Pack covers keep your pack dry in a rainstorm
This is a set of elastic cords and end stoppers so you can attach a water bottle to your shoulder strap.
This is available as an upgrade to the standard sternum strap that comes with the circuit. This strap features a magnetic closure allowing one handed operation while you hike.
Where to buy
ULA
The ULA Circuit is made by ULA Equipment, a small USA-made cottage company. You can only purchase it directly from ULA's website.
There are a few small, specialty retailers that sell ULA packs. These stores are located along the Appalachian Trail and Pacific Crest Trail. If you'd like to purchase from a small store, be sure to call first about availability.
Other Versions
Custom ULA Circuit
Weight: varies
Volume: 4,200 cu in
Max load: 35 lbs
You can also get a custom pack made specifically for you with color customization on pretty much every aspect of the pack, including made of other materials like X-Pac.
Other Backpacks to Consider
ULA Catalyst
Capacity: 60L
Weight: 2.75 lbs (44 oz)
Max load: 40 pounds
Materials: 100- and 200-denier Robic high-tensile strength nylon
Main Body Pockets: 1 large front pocket
Water Bottle Pockets: 2 (each holds 2 Smart Water bottles)
Hip Belt Pockets: 2 zippered
If you like the look of the Circuit but are looking for a little more room, the ULA Catalyst is a great option. This is the pack that I started with in 2018 before switching to the Circuit. The Catalyst has many of the same features as the Circuit, with an additional metal stay in the pack for support and a wider overall size, adding more available liters of storage. The Catalyst can also hold a BV 500 horizontally inside the pack.
If you are looking for a lighter pack the ULA CDT is a frameless lighter option for areas where you are not carrying heavy water loads or a hefty bear canister.
You can read our long-term, in-depth review of the ULA Catalyst backpack here.
Capacity: 60L
Weight: 1.9 lbs
Max load: 40 pounds
Materials: 100 & 200 denier Robic high-tensile strength nylon
Main Body Pockets: 1 large front pocket
Water Bottle Pockets: 2 (each holds 2 Smart Water bottles)
Hip Belt Pockets: 2 zippered
A framed pack similar in size to the Circuit is the Gossamer Gear Mariposa 60, which offers a similar load of 30 lbs and can carry 60 L. The Mariposa has unique side pockets for gear storage with one side having a top and bottom side pocket. There is also a top flap with a zipper pocket for quick access to maps or other small gear items.
The Mariposa also has a pocket for a sit pad, which provides extra padding on the back panel and padding when you take a break, so it is dual purpose. The Mariposa frequently is released in limited edition colorways, making it hard to resist when your favorite color is featured.
You can read our long-term, in-depth review of the Gossamer Gear Mariposa here.
Capacity: 55 L, also available at 40L
Weight: 31.6oz
Max recommended weight: 40 lbs
Material: DC H50 and DCH 150
Main body pocket: 1 front mesh netting
Water bottle pockets: 2 side mesh netting
Hip belt pockets: 2 sewn in on non-removable hip belt
The HMG Windrider 55 is an option to consider if you are looking to go lighter and don’t need a frame, as this pack shaves off a few ounces and has fewer features. It is another popular thru-hiker pack seen frequently on the long trails.
Capacity: 55L or 61L
Weight: 25 to 36+ ounces, depending on fabric, size, and add-ons
Max recommended weight: 35 lbs
Material: Ultra 200, Ultra X, ECOPAK, or Dyneema
Main body pocket: 1 front in UltraStretch
Water bottle pockets: 2 flat bottom pockets with drain hole
Hip belt pockets: No (An Ultra hip belt pocket is available for $30)
The LiteAF 46L Curve is a lightweight, durable pack with the volume and features to make it a great thru-hiking backpack. LiteAF offers a wide assortment of customization options, including extra pockets, over 40 pack colors and designs, three pack material options (Ultra, ECOPAK, and Dyneema), different top enclosures, and torso and hip-belt-specific sizing options. You can create your perfect pack.
If you aren’t on a time crunch and have a larger budget these are fun options for a custom pack.
You can read our long-term, in-depth review of the Lite AF Curve Full Suspension backpacking pack here.
About the Author / Why You Should Trust Us
I started backpacking 20 years ago and haven’t stopped. I thru-hiked the PCT in both directions and have done multiple loops around Tahoe on the TRT in addition to countless other trips and day hikes. My favorite hiking partner is my dog Ace who is always ready to gear up for an adventure. I love editing my backpacking gear closet trying to get the perfect kit for thru-hiking that is ultralight but still comfy. In the winter I can be found skiing, snowboarding and snowshoeing while I wait impatiently for the snow to melt so I can go backpacking on the long trails.
To see all of Sara Kruglinski stories, check her author page.
