Marmot Men's Never Summer 0° Sleeping Bag

The Marmot Never Summer 0° is a winter mummy bag with EN/ISO ratings of -8°C comfort and -16°C limit (extreme -37°C), a genuine four-season bag for cold backpacking rather than a general three-season all-rounder. It uses 850 g of 650 fill-power hydrophobic goose down, RDS-certified, at a total weight of 1450 g - a fill efficiency of about 1.88 g of down per gram of warmth, respectable but not class-leading given the modest fill power. Half-length dual-side zippers with two-way sliders let you vent top or bottom independently, useful across the four-season range, and a ventable footbox adds another way to dump heat. An adjustable, fitted hood, draft collar and draft tube handle the cold end. The 20D ripstop nylon shell uses recycled materials and PFC-free treatments throughout, a real sustainability angle, though the fabric itself is fairly light for winter abuse. Packed to 36 x 24 cm and cut for men up to 180 cm in Regular, this suits winter backpackers who want four-season warmth without expedition bulk, provided they stay well above -16°C.