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Hyperlite Mountain Gear Southwest 55 Backpack vs Hyperlite Mountain Gear Unbound 40L

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

Hyperlite Mountain Gear Southwest 55 Backpack is the lighter option — 3 g lighter than the Hyperlite Mountain Gear Unbound 40L (0% less weight). If grams matter to you, that is the one to beat.
Spec Hyperlite Mountain Gear Southwest 55 Backpack Hyperlite Mountain Gear Unbound 40L
Weight 850 g · 0.850 kg · 1.87 lb 853 g · 0.853 kg · 1.88 lb
Brand Hyperlite Mountain Gear Hyperlite Mountain Gear
Category Backpack Backpack
Hyperlite Mountain Gear Southwest 55 Backpack
850 g

Robust ultralight pack with Dyneema Composite Hybrid fabric and two aluminum stays. Ideal for technical terrain and variable weather conditions.

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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.

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Hyperlite Mountain Gear Southwest 55 Backpack vs Hyperlite Mountain Gear Unbound 40L: which should you buy?

If saving weight is your priority, the Hyperlite Mountain Gear Southwest 55 Backpack wins — at 850 g it is 3 g (0%) lighter than the Hyperlite Mountain Gear Unbound 40L (853 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.

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