The Big Agnes Crosho UL -20 Degree Sleeping Bag is a ultralight sleeping bag for sleeping in the extreme cold. Insulated with loads of 850 fill power DownTek(TM), this mummy shaped bag gets you snuggled up and right to sleep when the Snow and wind is howling outside your tent. Pull the hood close and the vertical baffles of the bag will wrap your body, holding heat closer through the night. Features of the Big Agnes Crosho UL -20 Degree Sleeping Bag Traditional mummy shape allows for light weight and increased thermal value Body mapped baffle construction optimizes themal efficiency 3D anti-snag draft tube prevents heat loss along the zipper Vertically structured side walls integrating contoured baffles trap heat closer to the body Contoured hood baffles Cradle the head for a more comfortable Fit Oversized interior anti draft collar Ergonomic foot box construction provides more loft and warmth Superlight shell fabric with High tear strength DownTek water repellent down repels water while maintaining insulating value Low profile cord lock lets you un-cinch the hood with one hand Minimal zipper cuts weight and reduces cold spots Zipper garage Interior fabric loops for sleeping bag liners Steam lined exterior loops for hang drying or storage Mesh storage sack and nylon stuff sack