Therm-a-Rest Corus™ 20F/-6C Quilt

The Corus 20F/-6C is Therm-a-Rest's three-season quilt, rated to a manufacturer comfort temperature of 0 °C and a limit of -7 °C. It uses 650-fill hydrophobic duck down, a lower fill power than the 900-fill goose down in Therm-a-Rest's Hyperion bags, compensating with more down mass: 530 g of fill inside a total weight of 730 g — trading some weight efficiency for a lower price than higher-fill-power alternatives. Construction is horizontal box-baffle rather than sewn-through, keeping the down lofting evenly instead of shifting into cold spots, and the shell uses 20D polyester with a DWR finish for basic weather resistance rather than full waterproofing. As a quilt it has no zipper or full enclosure; instead, SynergyLink-style pad loops attach it directly to a sleeping pad, closing the draft gap an open-backed quilt would otherwise have, while a trapezoidal footbox seals in warmth around the feet. Packed into its stuff sack it compresses to 29 x 19 cm. It suits backpackers already comfortable with quilt-style sleep systems rather than a traditional zippered bag, on three-season trips down to around freezing.