ULA Equipment
ULA Catalyst
The Catalyst is the Circuit's bigger sibling — 75 liters of total volume and a 40 lb rating for long food carries, winter kit, or bear-canister-plus-packraft loads. It's the UL pack for people whose trips outgrow the Circuit.
Price and availability on ULA Equipment’s site may differ.
Specifications
What do these specs mean? →Features
Pros
- ✓The go-to answer when r/Ultralight asks 'what if I need more than a Circuit' — same DNA, more capacity, 5 lb higher rating.
- ✓Dual aluminum stays plus the hoop make its 40 lb rating honest; desert hikers carry 8L of water without collapse.
- ✓75 liters swallows a BV500 horizontally plus 10 days of food — the specific use case owners buy it for.
- ✓The same 400d Robic bombproof reputation as the Circuit, with thousands-of-miles reports common.
- ✓Massive front mesh and hipbelt pockets keep a full day's needs outside the main bag.
- ✓Hand-made in Utah, easily repairable, backed by ULA's excellent service.
- ✓Only 5 ounces heavier than the Circuit for 7 more liters and a stiffer frame.
- ✓Strong resale on trade forums, like everything ULA.
Cons
- ✗Overkill for standard three-season loads — most buyers who don't need the volume end up wishing they'd bought the Circuit.
- ✗Same zero-ventilation foam back as the Circuit; sweat is the tax.
- ✗Fixed torso sizes with direct-order-only sizing risk.
- ✗At 2.65 lbs it's approaching crossover packs with plusher harnesses.
- ✗The big collar is floppy when underfilled, so partial loads need diligent compression.
- ✗No lid, no internal organization — the usual ULA minimalism.
- ✗Seasonal lead times can be long.
- ✗The look is pure function; nobody buys a Catalyst for style.
Common Questions
Compare the ULA Catalyst
Related backpacks
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ULA Equipment
ULA Circuit
The Circuit is the thru-hiking pack — hand-made in Logan, Utah by ULA Equipment and a perennial #1 in Halfway Anywhere's PCT gear survey. Its 68 liters of total volume, bombproof Robic fabric, and 35 lb carry make it the default recommendation for first thru-hikes. An Ultra-fabric version is sold at a premium.
Weight
2.47 lbs
Capacity
68 L
Frame
Internal Frame
ULA Equipment
ULA Equipment Ultra Circuit
The Ultra Circuit is the Ultra-fabric version of ULA's best-known pack. It keeps the Circuit's carbon hoop and aluminium stay combination but rebuilds it in Ultra 400X and 200X, making it waterproof and considerably more tear-resistant than the standard Robic version.
Weight
2.24 lbs
Capacity
68 L
Frame
Internal Frame
ULA Equipment
ULA Equipment CDT
The CDT is the largest of ULA's frameless packs and the cheapest way into the brand. UltraGrid is a doubled 200D recycled grid fabric that resists tears well beyond its weight, and ULA states a clear 25 lb ceiling rather than leaving it to inference.
Weight
1.69 lbs
Capacity
50 L
Frame
Frameless
REI Co-op
REI Co-op Flash Air 50
The Flash Air is REI's ultralight pack, using a shaped spring steel frame rather than stays or a hoop. It is the only pack in this group backed by a mainstream retailer's return policy, which matters more than usual in a segment dominated by made-to-order cottage brands.
Weight
2.0 lbs
Capacity
50 L
Frame
Internal Frame
The Aircontact Ultra is Deuter's move into genuine ultralight territory: 1,270 g for a 55 L framed pack with a roll-top closure and a removable lid. It keeps the Aircontact name and Air Spacer mesh but swaps the aluminium Y-frame for a spring-steel round-profile perimeter frame, which is where most of the weight saving comes from.
Weight
2.8 lbs
Capacity
50+5 L
Frame
Internal Frame
Also in 40+5 L
The women's-fit Aircontact Ultra, at 1,210 g for 50 L. Between this and the 35+5 SL at 1,140 g, it is the lightest framed pack Deuter offers in a women's fit, and one of very few ultralight packs with a genuinely women's-specific carrying system rather than a short size of a unisex design.
Weight
2.67 lbs
Capacity
45+5 L
Frame
Internal Frame
Also in 35+5 L