Hyperlite Mountain Gear Southwest 40L Backpack vs Osprey Sirrus 36
Weight and specs compared for 2026 — and which one to choose.
Fully waterproof Dyneema Composite Hybrid pack with aluminum stays and foam back panel. Built for off-trail use in harsh conditions. 29.7 oz.
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Hyperlite Mountain Gear Southwest 40L Backpack vs Osprey Sirrus 36: which should you buy?
If saving weight is your priority, the Hyperlite Mountain Gear Southwest 40L Backpack wins — at 841 g it is 379 g (31%) 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.