Keep yourself warm and comfortable for winter weather activities wearing this Gerbing 7V Heated Base Layer Top for Women. Designed to be worn under another garment as a base layer, this heat base layer has built-in heating panels on the chest and upper back that are powered by 7 Volt power bank for a soothing warmth for as long as 8 hours. This electric heated clothing is made from a soft and stretchy fabric mix of 92% polyester and 8% spandex for extended hours of working as well as tailgating, hunting, sports fun in cold environments. You can easily change the heat settings with the tap of a button to adjust your body temperature. Also, this battery heated base layer shirt is easy to care as you can wash it in your home washing machine on a gentle cycle. Please follow the cleaning instructions provided for the best results.