Designed to keep your knees, calves, thighs, and hips warm & cozy this winter. They're lightweight & thin, so you can wear them comfortably under any type of pants. Snug fit makes them ideal for climbing, snowboarding, biking, or just lounging around the house. Powered by a standard USB rechargeable power bank (sold separately). Be sure to grab another one if you plan to use it at the same time as your heated vest.