The Cordless Wrist Heat Therapy Wrap by Sharper Image uses Far Infrared Ray (F.I.R.) heat to melt away chronic pain. The infrared heat penetrates bone and muscle tissue, but doesn't get hot to the touch, making it ideal for those with sensitive skin. Features 4 adjustable heat settings and soft, stretchable fleece material. One size fits all (left or right wrist). The Cordless Wrist Heat Therapy Wrap by Sharper Image uses Far Infrared Ray (F.I.R.) heat to melt away chronic pain. The infrared heat penetrates bone and muscle tissue, but doesn't get hot to the touch, making it ideal for those with sensitive skin. Features 4 adjustable heat settings and soft, stretchable fleece material. One size fits all (left or right wrist).