Osprey Sirrus 36 vs Zpacks Super Nero Ultra 50L Backpack
Weight and specs compared for 2026 — and which one to choose.
Versatile ultralight frameless pack in Dyneema Composite Fabric. Sized for multi-day thru-hiking trips while staying under 350g total weight.
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Osprey Sirrus 36 vs Zpacks Super Nero Ultra 50L Backpack: which should you buy?
If saving weight is your priority, the Zpacks Super Nero Ultra 50L Backpack wins — at 345 g it is 875 g (72%) lighter than the Osprey Sirrus 36 (1,220 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.