The Cypress GWS from Western Mountaineering is incredibly wide, with more insulation and girth than any other bag in its warmth range. Even though this is not a mummy bag, it is absolutely capable of keeping a person warm at 30F 34C. With an average loft of 11 inches this bag will completely engulf your body with a thick barrier of the best thermal protection available, 850 fill power premium quality goose down. In fact, a Cypress GWS is a good way to surround yourself in warm goose down since each one is filled with about 50 ounces of it. Features include a stout insulated draft tube inside the zipper combined with a second storm flap covering the outside of the zipper, a Gore Windstopper outer shell material, a three dimensional insulated draft collar, and a second zipper allowing the bag to open up completely around the foot.