NEMO Sonic™ Down Mummy Sleeping Bag 0

The NEMO Sonic 0 sits a notch below its -20 sibling, rated to an ISO comfort of -10°C and limit of -18°C, which places it in genuine four-season winter territory without the extreme-cold overbuild of a full expedition bag. It uses 770 g of 800-fill-power hydrophobic goose down (RDS-certified) in vertical V-baffles within a 20D recycled nylon ripstop shell, for a warmth-to-weight ratio of 12.7 and about 79 g of bag weight per degree of comfort - solidly efficient, though behind the -20 model, since some hardware weight (footbox, zippers, hood) stays roughly fixed regardless of temperature rating. At 1420 g total, it carries a fitted hood, draft collar and tube, footbox venting, and an internal pocket, all wrapped in bluesign-certified, 100% recycled fabric with PFC-free treatment. The short-length sizing suits users up to 167 cm rather than taller hikers. This bag targets winter camping and shoulder-season alpine trips where -10°C to -18°C nights are realistic, rather than casual three-season backpacking, where its weight would be hard to justify.