Come and see our amazing products. Plastic case with stainless steel at the back. You can easily take it to your palm in cold days. It uses one touch button to control the heating status, which is indicated by LED light. It's single temperature is 48 degrees. It can keep 3hrs warming time. Except powered by the USB cable, 2 x AA battery could be also used. Pls confirm with us about the packing info, stock color and exact production time before placing your order.