Ready for battle When the winds are howling and the temperature has dropped to 40 degrees you're truly in a life or death situation. Whether you find yourself high in the Himalayas clamoring for your life, or deep in the San Juans contending to get a good nights rest, the Western Mountaineering Bison GWS is ready for battle. A whopping 42 ounces of 850 fill power premium down is responsible for keeping you warm within the Bison. Fully fluffed, that's an insane 10 inches of insulating loft ensuring that none of your body heat can escape the bag. To ensure that none of that loft migrates, horizontal and V Block side baffles keep the down in place and well distributed. At the zipper, offset insulated double draft tubes will not allow any heat to escape or cold spots to form. Inside the Bison's massive hood, you will find an integrated hood ruff to totally seal your face from the elements. When the wind is really whipping through your tent, bivy, or snow shelter, the Bison's Gore Windstopper fabric is key. This fabric extends through the hood and keeps the elements out while remaining breathable for calmer nights. The Bison is the crowning glory of Western Mountaineering and demonstrates their commitment to innovation and quality. Amazingly, this life saving bundle weighs in at just 4 lb. 10 oz. As an added bonus, the Western Mountaineering Bison is proudly made in the USA. Features and Benefits a 5 14 SpacingV Block Side Baffle keeps insulation where it belongs. a 6439 ShoulderFoot Girth leaves room to layer. a Full Down Collar ensures that there are no cold spots. a Insulated External Hood Ruff seals your face from the elements. a Offset Insulated Double Draft Tubes seal heat in at the zipper. a 10 Loft, 40Adeg F a 42 oz. Down Fill. a Shockingly light 4 lbs. 10 oz. total weight. a Made in the USA.