Water-Proof / Wind-Proof Outer Layer. Designed To Enclose Patrol and Intermediate Cold Weather Sleeping Bag For The Complete Modular Sleep System. 2-Way Nylon Zipper Allows For Top Or Bottom Ventilation. Zippers Are Non-Locking Sliders Which Self Repair If Snagged Or Jammed. Can Be Used Alone For Warmer Temperatures. Check out these listings for more great gear! Canteens and Hydration Carriers. Jackets, Coats, and Parkas.