Sea to Summit Trek Down Sleeping Bag 18

The Sea to Summit Trek Down Sleeping Bag 18 (TK II) is a three-season down bag with a semi-rectangular cut that offers more room to move than a classic mummy shape. Tested comfort is -1°C, limit -8°C, and the bag weighs 980 g. The fill is 500 g of 650 fill power duck down at a 60/40 ratio with hydrophobic treatment, and box-baffle construction keeps the down evenly distributed across the bag. A two-way, full-length zipper combined with a separate foot-box zipper lets the bag open flat as a blanket and lets ventilation be adjusted to temperature, while a 30D nylon shell and 20D polyester liner with DWR finish add durability. Sized for users up to 183 cm, it packs down to 40 × 18 cm, about 6.1 L. The roomier cut suits hikers who find a classic mummy bag too confining, at the cost of slightly more weight than narrower bags with comparable fill.