← Gear database

Hyperlite Mountain Gear Unbound 40L vs Osprey Eja Pro 55

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

Hyperlite Mountain Gear Unbound 40L is the lighter option — 23 g lighter than the Osprey Eja Pro 55 (3% less weight). If grams matter to you, that is the one to beat.
Spec Hyperlite Mountain Gear Unbound 40L Osprey Eja Pro 55
Weight 853 g · 0.853 kg · 1.88 lb 876 g · 0.876 kg · 1.93 lb
Brand Hyperlite Mountain Gear Osprey
Category Backpack Backpack
Hyperlite Mountain Gear Unbound 40L
853 g

Ultralight 40L pack in woven Dyneema Composite Fabric with internal frame stays and hipbelt. Ideal for fast alpine and thru-hiking missions.

Check price Full details →
Osprey Eja Pro 55
876 g

Women's sub-1kg thru-hiking pack built from UHMWPE fabric with an AirSpeed suspended mesh back and removable top lid.

Check price Full details →

Hyperlite Mountain Gear Unbound 40L vs Osprey Eja Pro 55: which should you buy?

If saving weight is your priority, the Hyperlite Mountain Gear Unbound 40L wins — at 853 g it is 23 g (3%) lighter than the Osprey Eja Pro 55 (876 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