Keep comfortably warm in treacherous winter weather conditions with Windproof Watch Cap. This beanie is made with light, warm, and incredibly durable acrylic material that will keep you comfortable winter after winter. The knit cap is lined with dependable insulating PTFE (Polytetrafluoroethene) material that is specially designed to protect your head from biting wind-chills. This machine-washable one-size-fits-most winter hat is perfect for keeping warm during your favorite outdoor winter activities.