Designed for the nights adjacent to high-alpine summit bids and deep winter dawn patrols, the Mountain Hardwear -40 Degree Down Phantom Gore-Tex Sleeping Bag defends you against brutal conditions. This bag features Gore WindStopper which seals out the coldest winds and resists moisture to protect the insulation. Mountain Hardwear filled the Phantom 850-fill goose down for effective, efficient insulation that comes in at a surprisingly low weight. Vertical sidewall baffles maximize loft and therefore warmth while the winter mummy cut efficiently adds space for cold-weather gear storage and extra layers. A centered, half-length zipper makes sitting up and getting in and out a breeze, while an ergonomic draft collar works with the face gasket to ensure heat won't escape at vulnerable points.