Specification:  Name: USB Heating Vest;  Color: Black;  Material: 85%Cotton & 15%Polyester;  Size: S,M,L,XL,XXL(Optional);  Heating level: 45-65 degree Celsius;  Heating zones: 4 zones;  Power supply: USB;  Input voltage: 5V;  Input current: ≥1.85A;  Powered by 5V/2.0A power bank is suggested. (power bank is not included)    Heating level:  Green light(Low level): approx. 45 degree Celsius (10000mAH power bank can keep heating for 5-14 hours);  Blue light(Medium level): approx. 55 degree Celsius (10000mAH power bank can keep heating for 4-11 hours);  Red light(High level): approx. 65 degree Celsius (10000mAH power bank can keep heating for 3-9 hours).     Heating zone:  Back upper area (10000mAH power bank can keep heating for 9-14 hours);  Chest & Back upper area (10000mAH power bank can keep heating for 5-7 hours);  Chest & Back upper & middle area (10000mAH power bank can keep heating for 3.5-5.5 hours);  Chest & Waist & Back upper & middle area (10000mAH power bank can keep heating for 3-5 hours).     Features:  3 Levels Temperature Setting, provides temperature from 45 degree Celsius to 65 degree Celsius, easy to switch.  4 Heating Zones, allows switch heating area for generate heat across specified body areas.  Built-in USB port and storage pocket for connecting power bank (power bank is not included).  Waterproof electronic element supports hand washing, dry-cleaning, and machine washing.     Washing Tips:  1, Take away your power bank before washing.  2, Put it into cold water that below 30 degree Celsius.  3, Do not twist or wring.     Package Included:  1 x Electric Vest. (power bank is not included)