1.Notice:This knee wrap need to be plugged In to use, no battery in the wrap so not retain heat always  2.Made of high elastic neoprene, skin-friendly, lightweight, warm and stretchy material. Adjustble with hook and loop fastner, one size fit most men women and teenagers  3.Our heated wrist brace has 3 levels adjustable temp of low/medium/High, adjust according to your needs, safe to use, no worry it'll scald wrist. Electric heating will warm your wrist and enhance blood circulation reduce knee pressure from the deep  4.Electric heater with USB cable, it can be plugged in any power supplies with USB port, such as power bank(5V/2A is recommended), car charger, laptop, desktop computer, etc 5.Convenient to use, you can use it at home, office, hotel, in the car when you are working, watching TV, reading, travel and driving. And also perfect for outdoor activities in cold seasons, such as Cycling, Biking, Motorcycle, Snowboarding, Snowmobile, Skiing, Camping, Hiking, Climbing, Hunting, Fishing, Ice-Fishing, Running, Walking, Trekking, Dance, Yoga and days out