Rab Mythic Ultra 180 (32°F) vs Therm-a-Rest Vesper 20F
Weight and specs compared for 2026 — and which one to choose.
Ultra-lightweight 3-season sleeping bag weighing just 14.1 oz (400g) with 900-fill hydrophobic goose down and titanium technology.
Full details →Ultralight quilt with 900-fill hydrophobic Nikwax Treated Down. Rated 20°F with neck baffle and footbox snap. Among lightest mainstream quilts.
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Rab Mythic Ultra 180 (32°F) vs Therm-a-Rest Vesper 20F: which should you buy?
If saving weight is your priority, the Rab Mythic Ultra 180 (32°F) wins — at 400 g it is 150 g (27%) lighter than the Therm-a-Rest Vesper 20F (550 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.