Sierra Designs DriDown Backcountry Bed 800-Fill 2 Season Sleeping Bag nylon 800 Fill DriDown Versatile integrated comforter wraps allows you to easily adjust to varying temperatures Insulated Hand/Arm Pockets provide insulation under your arms when comforter is used outside of the bag Sleeping pad sleeve secures your sleeping pad to create the experience of a fully integrated bed Catenary shaped opening is smaller than bag width so when you push out, the walls push in to seal out drafts