Mountain Equipment's Everest Sleeping Bag stays cozy from the Khumbu Glaciers to the Lhotse saddle. Its 850 fill goose down insulation is the loftiest down available, and the Drilite Loft shell protects the down with highly water resistant protection. Drilite Loft is exceptionally light and highly breathable to ensure a good night's rest in temperatures as low as 40F. Apart from being the loftiest, the Everest's high quality performance comes from Mountain Equipment's unique baffling process. Its V and trapezoid 2 1 baffle construction keeps the down in place for ideal heat retention, and the trapezium 6 footbox works with the DC8 hood to ensure exceptional warmth. Mountain Equipment's Expedition Fit gives this mummy bag extra space for your mountaineering outfit. The EXL top lining improves thermal efficiency and comfort.