Unlike typical heated clothing with bulky wires, this windproof fleece vest has a virtually undetectable heating element woven from carbon fibers that are five times thinner than human hair, delivering sustained warmth while allowing comfortable wear. Heat is generated through the carbon-fiber mesh sewn into the chest and back of the vest, and the laminated microfleece fabric is windproof and traps heat close to your body. The unobtrusive lithium-polymer rechargeable battery provides up to five hours of continuous use after a three-hour charge, and three heat settings are easily manipulated by a controller that stores comfortably in an interior pocket. Includes AC adapter. Hand wash. Slim fit; unisex size M. L, XL, and XXL. (2 3/4 lbs.)