USGI Sleeping Bag Case. Made from olive drab cotton. Water repellent (not waterproof). If the case were waterproof, all perspiration would condense in the sleeping bag making it heavy and cold. Being water repellent, it will protect you against moisture. It works by pulling the sleeping bag straps through the openings and lacing the bag and the case together. All snaps and closures are in good working condition. These are genuine Vietnam era surplus.