Mammut

Sphere Down Winter Sleeping Bag: 5F Down

To put it bluntly, staying warm while embarking on winter ascents in the high alpine is crucial, and the Mammut 5 Degree Down Sphere Down Winter Sleeping Bag helps you do just that. Designed specifically for cold winter backpacking or mountaineering, the Sphere features a bluesign approved ProlightTX material that's equal parts durable, highly compressible, breathable, and wind-resistant. This fabric construction not only ensures maximum temperature regulation, but also assures that the elements won't sap your precious warmth. A DWR treatment fends off light moisture, while the 800-fill goose down provides warmth in the face of cold temperatures as low as 5 degrees Fahrenheit. Additionally, the wave-shaped chambers prevent cold spots and bolsters the bag's heat retention, and the two-layer foot area helps maximize warmth.