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: 2100 g Comfort Temperature Rating: -29 Celsius Lower Limit Temperature Rating: -40 Celsius Extreme Temperature Rating: -68 Celsius Max User Height: 198 cm Packed Size: ø27 x 58cm CM Down Ratio: 90/10 Fill Power: 850+ Temperature Rating Comfort The temperature at which a standard woman can expect to sleep comfortably in a relaxed position. If you are female or consider yourself a cold sleeper, use this rating to decide the coldest temperature the sleeping bag is suitable for. We emphasise the Comfort temperature for our women’s specific sleeping bags. Lower Limit The temperature at which a standard man can sleep for eight hours in a curled position without waking. If you consider yourself a warm sleeper, use this rating to decide the coldest temperature the sleeping bag is suitable for. We emphasise the Lower Limit temperature for all our unisex sleeping bags. Extreme This is a survival only rating for a standard woman. Between the lower limit and the extreme rating a strong sensation of cold must be expected and there is a risk of health damage due to hypothermia. This is an extreme survival rating only; we do not recommend you rely on this rating for normal use. Sea to Summit Alpine III - Long Down Sleeping Bag