The Big Agnes Greystone 0° Sleeping Bag delivers technical, lightweight performance that excels on and off the trail with a high thermal value, compressibility, and comfort. The Greystone features R.D.S. Certified 600-fill DownTek insulation with a PFC-free water-repellent finish to combat damp conditions and maintain loft. The recycled shell and lining fabrics have also been treated with a PFC-free coating to provide an additional layer against moisture. The contoured hood follows the shape of your head with an insulated tube along the upper hood opening to seal out drafts when cinched. The Greystone left zip bag can mate with the right zip women’s bag, allowing you to share warmth with your tent mate.