Thermalite, a knitted fabric that is thermal, it also regulates body temperature as your body heats up whilst running, Soft to the touch, smooth and luxurious next to the skin. Keeps you snug and warm, double layer fabric. Lightweight and breathable. Contoured design for better ear coverage. Shaped centre back for pony tail comfort. Reflective trim for exellent visibility. 96% polyester and 4% elastane. Receive a Free Maxifuel Viper Active Energy Bar when you purchase this item.