Sea to Summit Ascent Down Sleeping Bag 15

The Sea to Summit Ascent Down Sleeping Bag 15 is a three-season down bag for hikers who need reliable insulation through spring, summer, and autumn without carrying the weight of a winter model. Tested to EN ISO 23537, its comfort rating of -3°C and limit of -9°C cover typical mountain nights outside the depths of winter. The 540 g goose down fill (750 fill power) sits in box-baffle chambers, which hold shape and even distribution better than simple sewn-through construction, and hydrophobic treatment plus RDS certification help the down keep its loft in damper conditions. Total weight of 1,020 g works out to roughly 113 g per degree — a higher figure that reflects a lighter three-season build rather than a dedicated winter bag. Foot-box ventilation and an internal pocket for small items are practical touches, and the coupleable design lets two compatible bags join for couples. Shell and liner in 20D recycled nylon keep weight down. Suited as a general-purpose bag for most of the season outside deep winter.