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