Eco - Friendly, Eco - Amical. This Warming Pad is Auto - Adhesive to Clothes. Keep warm for up to 12 hors ! Just stick the Heat Pad to your clothes on the area you like to keep warm, and get warming heat for up to 12 hrs! Great for cold winter days or nights, on skiing trips, ice fishing.... Size 5.5 x 4" DO NOT STICK THIS WARMING PAD TO YOUR SKIN !