Wristocat features interchangeable supports that magnetically attach. The therapy disc support brings variation and thermal relief to the standard wristocat offering. The Ultra Low Disc reduces the overall profile, prowling just millimeters above the surface. Great for lower profile input devices and laptop keyboards. Combo includes two standard Wristocat Supports, two Therapy Disc Add-Ons, and two Ultra Low Disc Add-Ons,.