1. Three layers of protection (selected high quality silicone + pressure resistant padding + mobile chassis). 2. Selected high quality silicone and ergonomically shaped for greater comfort and safety . 3. The mobile chassis is fitted with 3 wheels for easy movement on the floor. 4. Stretchy adhesive straps are fitted to the compression padding to prevent it from falling off the knee. 5. The compression padding and the mobile chassis are removable, so that the mobile chassis can be removed and the top two parts retained for use when laying on top of wooden boards or easily damaged materials.