How To Use: 1.Take out USB plug 2.Plug in removable charger 3.Switch on the removable charger 4.Press the chest temperature control switch for two second 5.Red light flashing,means heating automatic 6.After red light flashes for 5 minutes,then automatic turn to white light,means medium temperature 7.Manual adjustment has three level,red light means hign-temperature heating continuously. White light means medium heating continuously,blue light means low heating continuously 8.Press the chest temperature control switch for two second,lights out and stop heating Temperature Shift(Manual adjustment) Warm:45 (Red Light) Comfort:35 (White Light) Energy Saving:25 (Blue Light) Specifications: Style: Sleeveless Vest Material: Polyester Power Supply Interface: USB Function: Keep warm, Anti water splashing and Prevent cold Size: M/L/XL/2XL/3XL/4XL Size: M, Length: 65cm, Bust: 53cm, Sleeve: 61cm, Shoulder: 43.8cm Size: L, Length: 67cm, Bust: 55cm, Sleeve: 62.5cm, Shoulder: 45cm Size: XL, Length: 69cm, Bust: 57cm, Sleeve: 64cm, Shoulder: 46.2cm Size: XXL, Length: 71cm, Bust: 59cm, Sleeve: 65.5cm, Shoulder: 47.4cm Size: XXXL, Length: 73cm, Bust: 61cm, Sleeve: 67cm, Shoulder: 48.6cm Size: XXXXL, Length: 75.5cm, Bust: 63.5cm, Sleeve: 68.8cm, Shoulder: 50.1cm Package Included: 1X Jackets(Mobile Power Not Included)