Never have sore knees again when you use the NoTrax Knee Rx Rug - Black. At a full 1 inch thick, this work surface is designed for comfort and durability in extreme kneeling application on gravel, asphalt, concrete, dirty and oily surfaces, tile and wood flooring, metal grating, and grass. Made of self-extinguishing, non-conductive, and silicone-free Nitrile/PVC foam, it is resistant to oils and greases. The built-in handle makes it easy to carry and the heavy-duty version features a laminated, rubber bottom for long-lasting wear on rougher surfaces. This mat is intended for commercial use.