Good2Go Medium 9 x 12 * Plush multi-ply cover design focuses moist heat right where you need it most * Joint-specific or multi-use shapes for a snug secure fit * Portability convenience and economy in a reusable unit that will last for years * Patented non-allergenic fill does not leak smell decay or encourage fungus growth * Fill has a special porous surface to trap the maximum amount of atmospheric moisture * Wide elastic strap holds heat snugly in place while you continue regular activities * Mitt is filled with two soft gel-packs that can be heated or frozen as needed to surround your hand with either hot or cold therapy