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Osprey Atmos AG 50 vs Zpacks Nero Classic Ultra Backpack
Weight and specs compared for 2026 — and which one to choose.
Zpacks Nero Classic Ultra Backpack is the lighter option — 1,611 g lighter than the Osprey Atmos AG 50 (85% less weight). If grams matter to you, that is the one to beat.
Zpacks Nero Classic Ultra Backpack
289 g
Frameless ultralight backpack made from Dyneema Composite Fabric. Minimalist design for SUL hikers. Top-loading with roll-top closure.
Check price Full details →Osprey Atmos AG 50 vs Zpacks Nero Classic Ultra Backpack: which should you buy?
If saving weight is your priority, the Zpacks Nero Classic Ultra Backpack wins — at 289 g it is 1,611 g (85%) lighter than the Osprey Atmos AG 50 (1,900 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.