Floortex Original Polycarbonate chair mats provide the ultimate quality, durability and clarity. Twice the impact strength of vinyl to provide a perfect easy glide ergonomic surface for caster based chairs. Polycarbonate will not curl, crack, dimple, discolor or smell under normal use. High clarity allows the beauty of flooring to shine through. Manufactured using 50% renewable energy. Gripper back for plush pile carpets over 0.5" thick.