This is a large cartoon usb heating foot warmer treasure USB foot warmer shoes can be removed and washed.The heat-able shoe is heated using a charger or portable power source and comes in two sizes and two colors each. In addition; there are adjustable and non-adjustable styles; you can choose according to your own needs.Sole material is foam; uppers use super soft velvet; the design of the root is more comfortable and warm; Small size is suitable for 36-39; and large size is suitable for 38-41.Please use 5v2a/6v2a power converter; please do not use less than 5v2a/ or more than 6v2a converter; otherwise it will cause poor heating effect/high temperature effect.