How To Use:1.Take out USB plug2.Plug in removable charger3.Switch on the removable charger4.Press the chest temperature control switch for two second5.Red light flashing,means heating automatic6.After red light flashes for 5 minutes,then automatic turn to white light,means medium temperature7.Manual adjustment has three level,red light means hign-temperature heating continuously.White light means medium heating continuously,blue light means low heating continuously8.Press the chest temperature control switch for two second,lights out and stop heatingTemperature Shift(Manual adjustment)Warm:45 (Red Light)Comfort:35 (White Light)Energy Saving:25 (Blue Light)Specifications:Style: Sleeveless VestMaterial: PolyesterColor: Black, BlueSize: M/L/XL/2XL/3XL/4XLPower Supply Interface: USBFunction: Keep warm, Anti water splashing and Prevent cold