If your going some where very cold then this is what you may need. The Cumulus Expedition 1100 is the warmest bag they make with a -40 degees C comfort rating. Differential fill and differential cut Box foot - comfortable, trapezium shape, for all feet positions Cowl hood with one hand operated drawcord Insulated neck baffle with velcro fastener and elasticated, one hand operated drawcord Full length, two-way YKK zip plus velcro fastener Left and right handed zip models available, which can be zipped together if required Anti-snag, full length zip baffle, down-filled to prevent cold spots Inside pocket and hanging loops Supplied with fully-featured stuff sack and breathable, mesh storage bag 'Brick' (offset, double boxwall) construction White, Diamond Grade, Super Goose Down - 96:4 Fill Power - 870 Pertex Ripstop ENDURANCE used for the outer shell and in critical internal sections (hood and feet) Waterproof Pertex ENDURANCE fabric is used, not just for the outer, but also in those parts of the inner which could get wet in extreme conditions. These include the hood inner and the sections around the feet. Weight - 1770g