The Puma GWS is at home for deep winter mountaineering endeavors. This sizable bag is lofted with down and roomy to boot! 37 ounces of 850+ fill power down lofts this bag to a full 9″ for a rating of minus 25 below! A shoulder girth of 64″ provides room to layer, store clothing or fit to big folk. The inside foot section is sewn with a 2.4 oz. fabric to protect the bag while stowing gear. And the Reverse Differential Hood is roomy, down-filled and warm, and totally made with Gore Windstopper™. The fully down-filled collar and both Interlocking Draft Tubes are also completely made with Gore Windstopper™ fabric. No place to cut costs! Few continents require anything warmer than our Puma Gore Windstopper™!