Sea to Summit Ember XT 0°C Sleeping Bag vs Therm-a-Rest Vesper 900
Weight and specs compared for 2026 — and which one to choose.
Ultralight 0°C rated bag with 850+ UltraDry Down insulation. Stretch-knit lining and sculpted hood for packability and comfort.
Full details →Ultralight sleeping bag with 900 fill-power hydrophobic goose down. 360g of down fill. Excellent warmth-to-weight ratio for three-season backpacking trips.
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Sea to Summit Ember XT 0°C Sleeping Bag vs Therm-a-Rest Vesper 900: which should you buy?
If saving weight is your priority, the Therm-a-Rest Vesper 900 wins — at 550 g it is 59 g (10%) lighter than the Sea to Summit Ember XT 0°C Sleeping Bag (609 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.