If there's one thing about weather, it's unpredictable. The U.S. Military solved the problem with this 3-layer ECW Sleeping Bag System. Use one layer for your next night in a drafty cabin. Use another for chilly Fall tent camping. When the bitter cold bites deep, you can use all 3 together for the ultimate in extreme weather comfort. Be prepared! Rated component of U.S. Military Extended Cold Weather System 3 Bags used together or separately to modify comfort rating Breathable GORE-TEXA(R) 100% waterproof Bivy Bag with taped, no-leak seams for all-night peace-of-mind Patrol Sleeping Bag is comfort rated +30Adeg to +50AdegF Intermediate Mummy Bag comfort rated +30Adeg to -10AdegF High-loft 100% nylon insulation in Patrol and Intermediate Bags for dependable warmth Heavy gauge zippers made to strict military specs All Bags pack into included Stuff Sack for easy transport and storage