← All gear comparisons

ULA Ohm 2.0 vs Zpacks Arc Blast 55L

Weight and specs compared for 2026 — and which one to choose.

ULA Ohm 2.0 is the lighter option — 13 g lighter than the Zpacks Arc Blast 55L (2% less weight). If grams matter to you, that is the one to beat.
shopping_cart Check today's price on Amazon
Spec ULA Ohm 2.0 Zpacks Arc Blast 55L
Weight 567 g · 0.567 kg · 1.25 lb 580 g · 0.580 kg · 1.28 lb
size Medium torso (20-23 in) / Medium belt (30-36 in); product discontinued
Brand ULA Zpacks
Category Backpack Backpack
ULA Ohm 2.0
567 g

Ultralight 50L frameless pack with framesheet option.

See it in your base weight → Full details →
Zpacks Arc Blast 55L
580 g

Frameless Dyneema pack with excellent load carry for its weight.

See it in your base weight → Full details →

Building a pack? Add either one to your HikeLoad list, or drop its weight into the base weight calculator, and see what it does to your total weight.

HikeLoad is reader-supported. As an Amazon Associate we earn from qualifying purchases, at no extra cost to you. Learn more.

ULA Ohm 2.0 vs Zpacks Arc Blast 55L: which should you buy?

If saving weight is your priority, the ULA Ohm 2.0 wins — at 567 g it is 13 g (2%) lighter than the Zpacks Arc Blast 55L (580 g). That said, the heavier option may justify the extra grams with more capacity, durability or comfort, so weigh the trade-off against how you'll use it.

See where both rank against everything else in this category on the lightest backpack page, or browse the full gear weight database.

More backpack comparisons

ULA Ohm 2.0 vs Zpacks Nero Classic 50L ULA Ohm 2.0 vs Zpacks Super Nero Ultra 50L Backpack ULA Ohm 2.0 vs Zpacks Arc Haul Ultra 50L ULA Ohm 2.0 vs Outdoor Vitals Carbon Evo 50 Backpack ULA Ohm 2.0 vs ULA Circuit ULA Ohm 2.0 vs ULA Catalyst