Features： 1、The humanized heating part design protects the waist and abdomen which are vulnerable to cold. 2、When heating, it needs to be connected to a mobile power supply, 5V power supply, stable performance, safe and durable, far lower than the 36V standard of the human body. 3、Technological temperature control design, double?layer heat preservation, one?key heating, three?speed temperature control, 5 seconds heating. 4、The internal heating wire adopts imported conforming fiber wire. Unlike the metal copper wire, which conducts electricity, the washing machine can also be cleaned (unplug the power when washing). 5、It is made of healthy and safe materials, and can be used with confidence. Specification： Condition: Item Type: Electric Heated Vest Main Fabric Composition: 100% polyester fiber Lining Composition: Cotton Style: cardigan Quantity of Floors: 3 floors Neckline Shape: V-neck Three Levels Of Temperature Control: 45℃ for energy saving, 50℃ for comfort and 55℃ for warmth Features: 5 seconds rapid heating, intelligent temperature control, washable, long-lasting battery life, far infrared heating, cold resistance and antifreeze, hot compress to keep warm SizeLengthShoulderLower HemBust L53cm / 20.9in42.7cm / 16.8in44cm / 17.3in94cm / 37in XL54cm / 21.3in43.9cm / 17.3in46cm / 18.1in98cm / 38.6in XXL55cm / 21.7in45.1cm / 17.8in48cm / 18.9in102cm / 40.2in XXXL56cm / 22in46.3cm / 18.2in50cm / 19.7in106cm / 41.7in Instructions: 1. Take out the USB plug; 2. Connect to the power bank; 3. Press the power bank output switch; 4. Long press the chest temperature control switch for 2 seconds; 5. The red light flashes, it is automatic temperature control heating; 6. Automatically turn blue light to medium temperature control; 7. Manually adjust to 3 gears, the red light is for continuous high temperature heating, the blue light is for continuous medium temperature heating, and the green light is for continuous low temperature heating; 8. Long press the chest temperature control switch for 2 seconds, turn off the light to stop heating. Washing instructions: Take out the power bank and add neutral detergent to hand wash or machine wash. Do not rub or beat strongly. You can use the washed clothes after natural ventilation and drying. Package List： 1 x Electric Heated Vest