Cleartex Ultimat Xxl Polycarbonate Chair Mat For Hard Floors, 60 X 60, ClearTwice the impact strength of PVC for a rigid easy glide surface for maximum ergonomic performance.High clarity to allow the beauty of your flooring to shine through.Polycarbonate will not adversely affect polished or varnished wooden floors. WARNING: This product can expose you to Bisphenol A (BPA), which is known to the State of California to cause Birth Defect/Reproductive Harm. For more information go to www.P65Warnings.ca.gov. - Birth Defect/Reproductive Harm:Bisphenol A (BPA)