Using advanced scientific reactions, the Calor Jacket works with your own body heat, however little that may be, to warm you beyond anything youâ??ve experienced. Ultra Quiet Water Resistant Softshell Construction, Durable And Soft Tricot Lining, Heatwave Ceramic Print For Additional Warmth, Backpack Friendly Hand warmer Pockets, Offset Vertical Chest Pockets, and Silvadur Antimicrobial Technology For Odor Management.