Description Our first choice for extreme cold and high altitude conditions where sleeping well can make or break an expedition. Designed for high altitude mountaineering and arctic conditions, the contoured mummy design delivers efficient insulation, while our updated expedition sizing provides space for extra clothing to be worn inside the bag. The anatomically shaped and oversized footbox can comfortably accommodate boots when necessary. Features Contoured mummy shape for efficient insulation Expedition sizing for extra space and layered clothing Anatomically shaped and oversized footbox can accommodate boots Free-Flow half right-side zip for freedom of movement and additional ventilation Large internal security pocket Includes lightweight Ultra-Sil™ compression bag and storage cell Specifications Weight: 1870 g Comfort Temperature Rating: -29 Celsius Lower Limit Temperature Rating: -40 Celsius Extreme Temperature Rating: -68 Celsius Max User Height: 183 cm Packed Size: ø27 x 58 CM Down Ratio: 90/10 Fill Power: 850+ Sea to Summit Alpine III Down Sleeping Bag