No cold can turn you away when you?re hunkered down in your Bristlecone. This bag is built big and warm and big! 69? of girth at the shoulder and 48? of girth at the foot. Crammed with 42 oz. of 850+ down yields an unrelenting 8 1/2? of simmering loft that keeps you heated to -10?. A large draft tube and the down filled collar make certain that winter remains outside. With 2 zippers it can be zipped to our mummy bags or unzipped to lie flat. In spite of its roomy proportions the Bristlecone weighs only 3 lbs. 15 oz.