Therm-a-Rest Saros™ 0F/-18C Sleeping Bag

The Saros 0F/-18C is a winter synthetic mummy bag, an alternative to down for hikers who want reliable insulation even in damp conditions. The eraLoft fill weighs 1610 g and delivers a -10°C comfort rating and -18°C limit, placing it in the four-season/winter category. That synthetic insulation comes at a weight cost — 1960 g total puts the Saros among the heavier bags in the catalogue, but it's less sensitive to moisture than down and needs less careful handling. The shell is 20D polyester with DWR treatment, lined with 20D polyester taffeta. A contoured hood, draft collar, and draft tube limit heat loss, and a three-quarter-length zipper trims weight compared with a full-length one. SynergyLink loops allow the bag to be anchored to a sleeping pad. A listed maximum user height of 167 cm suggests a shorter cut than most other bags in the line, so it's worth checking fit against your own height before buying. Both a stuff sack and storage sack are included.