Description This is a bag for the serious mountaineer, planning on spending some quality time with Mother Nature's dark side. It is a serious bag for serious conditions. Comfort rated to -15°C, and extreme rated to -40°C, this sleeping bag will keep you warm in some of the coldest environments. Features Differentially cut (outer is cut bigger than inner) 3-Dimensional construction Overfilled chest and foot sections Built-in cowl and oversized inside hood ensures a snug fit Twin collar baffle for maximum heat retention Tested on Mt. Everest Available in large size (10 cm longer and 8 cm wider) Specifications Weight: 2.6 kg Comfort Temperature Rating: -15°C Lower Limit Temperature Rating: -25°C Extreme Temperature Rating: -40°C Dimensions: 225 x 82/55 cm Packed Size: 22 x 39 cm Down Ratio: 92/8 Fill Power: 650 Material(s) Microtex Ripstop Nylon (Outer), Microtex 5000 (Inner) First Ascent Blue Wolf Down Sleeping Bag