Specialized DesignedDesigned for HARD FLOOR surfaces only. No gripper. Thickness 0.088243 thicker, anti-slide coating on the underside which is designed to keep them firmly in place while in use. Best ProtectionEffectively helps to prevent damage to hard flooring caused by your office chair casters or wheels. Under standard use will not crack, curl, break, scratch or discolor. SpecificationsThis PVC chair mat is ergonomically designed to provide added ease of movement, it8217s very flexible, which proven to reduce leg fatigue by taking the strain off your legs.