Big Agnes Anthracite 20F Degree Mummy Sleeping Bag - Slate Grey - Synthetic-fill traditional mummy sleeping bag. Big Agnes Anthracite 20 degree traditional mummy style sleeping bag is designed to be taken anywhere and provide rest after a long day outside. Stay cozy with Fireline PRO Eco recycled synthetic insulation and a roomier mummy shape than a traditional bag design. Lightweight enough to stuff in your pack for summer backpacking but comfortable enough for backyard campouts with the kids, this bag is so versatile and comfortable you'll want to take it on every outing! Feature Traditional mummy shape allows for light weight and increased body heat retention Contoured hood follows the shape of your head for a more comfortable fit Oversized no-draft collar and no-draft zipper to keep the cold out Low-profile cordlock lets you uncinch the hood with one hand Insulated tube along upper hood opening seals out drafts when cinched