ULA Equipment Circuit Review

Overview

The ULA Equipment Circuit is a 68L, internally framed pack made in Logan, Utah, that has quietly become one of the most trusted names on long trails. It’s been the most popular pack on the Pacific Crest Trail for four consecutive years and the top-used pack on the CDT according to the Halfway Anywhere annual survey. Built around 400D Robic nylon, a smart three-part suspension, and an unusually wide range of fit options, the Circuit is one of the best ultralight and thru-hiking packs around — available in a wide range of sizes and offering impressive load-carrying for its weight.

Key Specs

Spec	Value
Weight	1092 g (38.5 oz)
Volume	68 L / 4,200 cu in
Max Load	35 lbs
Material	ULA 400D Robic Nylon
Frame	Carbon fiber + Delrin hoop, foam framesheet, single aluminum stay
Shoulder Straps	J or S-shaped (choose at order)
Hip Belt	Replaceable; 6 sizes; dual-strap inward-pull adjustment
Side Pockets	2 (each holds two 1L bottles)
Front Pocket	UltraStretch mesh (2024 update)
Closure	Roll-top with side compression straps
Bear Can	Every canister on the market fits vertically
Warranty	Lifetime
Price	$300 (Robic)
Comparison	See how ULA Circuit compares to similar gear

Performance

Suspension and Load Carry

The Circuit’s frame is the first thing that sets it apart from the frameless crowd. It uses a 1.2 oz carbon fiber and Delrin suspension hoop in conjunction with a dense internal foam frame and a single aluminum stay to give excellent back panel support, maximum load control, weight transfer, and pack rigidity without limiting range of movement.

In practice, that setup works. Across multiple trips in southwest Texas and the New Mexico badlands — requiring extra water carries in desert conditions — testers carried up to 35 pounds comfortably. The carrying capacity comes courtesy of a multi-part suspension consisting of the hard foam framesheet, the carbon-fiber-and-hard-plastic hoop, and the aluminum stay. During testing in the Rocky Mountains with loads up to 34.5 lbs, the robust suspension provided excellent load transfer to the hips via the carbon fiber and Delrin hoop frame, dense foam back panel, and single aluminum stay. That said, when pushed near its 35 lb max comfortable load, it begins to feel a tad shoulder-heavy. Stay inside the recommended range and you’re fine; try to push past it for days at a time and you’ll feel it.

The one tradeoff is back breathability. The foam back panel doesn’t offer the same no-holds-barred airflow that you get from a suspended mesh back panel like that of the Zpacks Arc Haul, but the Circuit still provides an almost unbelievable amount of comfort for an ultralight backpacking pack.

Fit and Customization

This is where ULA genuinely outpaces almost every competitor. You can choose from four torso sizes and six hip belt sizes, plus two types of shoulder straps (“J” and “S”). The hip belt uses a clever two-strap inward-pull adjustment that lets you dial load transfer without loosening the whole system mid-hike. The ability to adjust the angle of the load lifters is a premium feature normally found only on high-end expedition or custom-made backpacks, not typically found on lightweight or ultralight packs. The hip belt is also replaceable, so if your body changes or you just want to swap sizes, you’re not buying a new pack. The velcro hip belt attachment block is taller than it needs to be by about 2 inches, so you can raise or lower the hip belt and effectively adjust torso length — the convenience of adjustable torso length without the added weight and complexity it usually requires.

S-straps are worth mentioning here. The shoulder straps are available in J-shaped or S-shaped styles to accommodate people with breasts or wide chests, which is one of the key reasons ULA has more female customers than any other ultralight backpack company. I’ve heard enough firsthand reports from women on the PCT who swear by the S-straps to take that seriously.

Organization and Storage

With 68 liters of total capacity, the Circuit is one of the highest-volume ultralight-style backpacks you can buy. Most of the storage is in a large main compartment that secures with a roll-top closure, which provides excellent top compression for larger loads without requiring any additional weight from a top lid.

The roll-top closure makes the pack’s size highly adjustable — it expands to fit a full bear canister vertically in the main compartment, then rolls away when carrying smaller loads that require less space.

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’re transitioning from a pack with separate organizational pockets and a brain.

That’s a fair heads-up: this is a top-load pack and you need to pack with intention.

The 2024 updates added an UltraStretch mesh front pocket (abrasion-resistant), ice axe/trekking pole loops, and removable top/bottom straps for attaching gear like sleeping pads or bear cans.

Good moves across the board.

Durability

Durability has been great across multiple Circuits. The Robic fabric is quite tough and can take a beating, showing some wear after extended use and thousands of miles, mostly on the bottom of the pack where it’s set down on abrasive terrain. The only tear reported was on a hip belt pocket (which uses a lighter ripstop) from a branch during off-trail travel — quickly fixed with a Tenacious Tape patch.

Several owners have backpacked over 3,000 miles with their Circuit and report it still holding up.

For what it’s worth, the pack is waterproofed with three passes of Teflon DWR and three passes of PU on top of the 400D Robic fabric. Because the water resistance comes from a chemical coating rather than a physical barrier, it will need to be re-treated at some point — but analysts who’ve used it on multiple thru-hikes largely just use a pack liner or cover as needed. Carry a cheap pack liner if you’re hiking in reliably wet conditions. That’s true of most packs in this category.

Pros & Cons

Pros

• Best-in-class hip belt with replaceable, multi-size options and dual-strap inward adjustment
• Genuinely exceptional fit customization — 4 torso lengths, 6 hip belt sizes, J/S strap choice

• 68 liters of total capacity — one of the highest-volume ultralight-style packs available with few peers

• Bear canister compatible (every canister fits vertically)

• Versatile and durable at a reasonable price and weight

• Made in the USA with a lifetime warranty
• Overwhelmingly praised customer service — ULA will work with you post-purchase on fit

Cons

• Back panel foam lacks breathability compared to suspended-mesh competitors like the Arc Haul
• Not waterproof — seams are not taped, so a pack liner is wise in sustained rain

• Can’t stand upright while loading — the rounded bottom requires leaning it against something, a result of the curved rear design

• A few ounces heavier than what the most weight-conscious hikers may prefer

• The simple single-compartment design can feel like an adjustment if you’re coming from a pocketed, top-lid pack

• The frame isn’t for everyone — some users who prefer the body-hugging feel of a frameless pack find it doesn’t suit them

Who Should Buy This

If you want 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

— especially if you’re anywhere from shorter overnighters up to a full Triple Crown attempt.

If you have your total pack weight down to around 30 pounds and want to feel the freedom of traveling light, this is the pack for you.

It’s particularly well-suited for hikers who’ve struggled to find a pack that fits their body in mainstream retail — ULA’s sizing matrix and willingness to talk through fit on the phone is legitimately rare at this price point. Gram-counting fastpackers with a sub-10 lb base weight will do better with something lighter and frameless; everyone else should take a hard look at the Circuit.

Verdict

The ULA Circuit is about as close to a consensus recommendation as the thru-hiking world gets. It’s a workhorse that can take you from Mexico to Canada, handles pretty much anything most lightweight backpackers will throw at it, and is reliable, durable, and comfortable enough that owners aren’t sure when they’d ever need to replace it. At 1092g it’s not a weight-weenie choice, but those grams buy you a suspension system, fit options, and durability that frameless packs simply can’t match. Rating: 9/10.