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Rab Mythic Ultra (20°F) vs Western Mountaineering Ultralite 20F Sleeping Bag

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

Rab Mythic Ultra (20°F) is the lighter option — 122 g lighter than the Western Mountaineering Ultralite 20F Sleeping Bag (15% less weight). If grams matter to you, that is the one to beat.
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Spec Rab Mythic Ultra (20°F) Western Mountaineering Ultralite 20F Sleeping Bag
Weight 700 g · 0.700 kg · 1.54 lb 822 g · 0.822 kg · 1.81 lb
Brand Rab Western Mountaineering
Category Sleep System Sleep System
Rab Mythic Ultra (20°F)
700 g

Winter-capable sleeping bag at 24.7 oz (700g) with 900-fill hydrophobic down, ideal for 3-season to winter transition camping.

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Western Mountaineering Ultralite 20F Sleeping Bag
822 g

Hand-sewn sleeping bag, 29oz, 850+ fill power goose down, three-season

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Rab Mythic Ultra (20°F) vs Western Mountaineering Ultralite 20F Sleeping Bag: which should you buy?

If saving weight is your priority, the Rab Mythic Ultra (20°F) wins — at 700 g it is 122 g (15%) lighter than the Western Mountaineering Ultralite 20F Sleeping Bag (822 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 sleep system page, or browse the full gear weight database.

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