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Marmot Plasma 15°F vs Western Mountaineering Ultralite 20F Sleeping Bag

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

No winner on weight yet. The recorded weights have not both been verified on the same basis. Size, included parts and single-item versus pair weights can differ. Check the linked sources before choosing a replacement.

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Spec Marmot Plasma 15°F Western Mountaineering Ultralite 20F Sleeping Bag
Weight 850 g · 0.850 kg · 1.87 lb 822 g · 0.822 kg · 1.81 lb
size Regular (6'0")
Brand Marmot Western Mountaineering
Category Sleep System Sleep System
Marmot Plasma 15°F
850 g

800-fill down sleeping bag rated to 15°F (-9°C).

See it in your base weight → Full details →
Western Mountaineering Ultralite 20F Sleeping Bag
822 g

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

See it in your base weight → Full details →

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Marmot Plasma 15°F vs Western Mountaineering Ultralite 20F Sleeping Bag: which should you buy?

The listed weights alone are not enough to choose between these products. Confirm the size, included parts and weight basis against each source; choose equipment for the function and fit you need.

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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