Description The Blue Wolf Down sleeping bag is ideal for the serious mountaineer who plans on spending some quality time with Mother Nature's dark side. This is a serious bag for serious conditions, such as Mt Everest or Antarctica. Comfort rated to -15°C, and transition rated to -25°C, this sleeping bag will keep you warm in some of the coldest environments on earth. Don't take any shortcuts when it comes to adventure, remain insulated, comfortable and well-rested on your next extreme outdoor pursuit Features Differentially cut (outer is cut bigger than inner) 3-Dimensional construction Overfilled chest and foot sections to expertly retain heat Built-in cowl and oversized inside hood ensures a snug fit Twin collar baffle for maximum heat retention Shell fabric: 40D 290T Mini R/S Nylon with white milky coating 3K/3K (breathability and waterproof) Tested on Mt. Everest Also available in standard size (10cm shorter and 8cm narrower) Lining: 50D 320T Micro Poly D/P by construction. Specifications Weight: 2.64 kg Comfort Temperature Rating: -15°C Lower Limit Temperature Rating: -25°C Extreme Temperature Rating: -40°C Dimensions: 240 x 90/60cm Down Ratio: 92/8 Fill Power: 650 Material(s) Microtex Ripstop Nylon (Outer), Microtex 5000 (Inner) First Ascent Blue Wolf Down Sleeping Bag - Large