polyester fabric and filled with cotton Imported Zipper closure Machine Wash Noted: Battery Included 5V 10000mAh power bank with USB port. If you do not receive a battery, please contact our seller immediately and we will send you a battery free of charge. 5 Heating Areas & 3 Temperature Adjustments : The heated vests are included 5 carbon fiber heating elements generate heat across the upper, lower back and belly, 3 heating settings: 56/ 46/39 with the carbon fiber heating system. Safety Design & Lasting Warmth : Using 5 volt safety voltage, a 1000mAh power bank can last to heat for 6-8 hours. 5 built-in carbon fiber heating elements, which bring warmth to the human body by heating the carbon fiber filaments. Skin-friendly Fabric & Easy Care: 100% nylon gives you incredible durability and comfort. The heated vest is designed to be machine washable. (Put the data cable of the heating vest into the zipper bag before washing) Quick Heating Vest: Aptoco Warm Heated Vest heats up quickly in one minute. Allowing you to enjoy outdoor activities such as camping, hunting, fishing, skiing, hiking or watching football games in chilly weather.