Air Activated Heating Vests TechNiche's Air Activated Heating Vests with HEAT PAXâ„¢ Body Warmers deliver a total of 16 hours of warmth. They are an effective defense against the cold. Heating can be suspended at any time by resealing the inserts in an airtight container or plastic bag.   Air Activated Heating 5529 ThermaFurTM Ultra Fleece Vests High collar w/zipper closure and two zippered pockets; ideal for a wide range of cold weather applications Soft, durable, water repellant upper body softshell fabric w/ poly-fleece lower body fabric w/black cotton-poly elastic trim, and a total of eight (8) built-in Body Warmer pockets four (4) front, four (4) back for total body comfort Black/Black, Black/Royal Blue, Black/Khaki XS, S, M, L, XL, 2XL, 3XL Include eight (8) HEAT PAXTM Body Warmers (5540) for up to 20 hours of warming relief for your body     Air Activated Heating 5527 ThermaFurTM Deluxe Fleece Vests High collar, handy front pockets, and zipper closure; deliver additional coverage and protection where you may need it most Soft, durable, 100% poly-fleece shell w/black cotton-poly elastic trim, and a total of eight (8) built-in Body Warmer pockets four (4) front, four (4) back for all around body comfort Royal Blue, Black, Khaki S, M, L, XL, 2XL, 3XL Include eight (8) HEAT PAXTM Body Warmers (5540) that deliver steady, comfortable heat to your torso for up to 20 hours