Mammoth Office Products Polycarbonate Office Chair Mat for Low to Standard Pile Carpets, 36" x 48" Rectangular Polycarbonate mats free of phthalates, PVC, tin, lead, and cadmium Extreme durability for years of use, Guaranteed not to crack, chip, break or shatter under normal use and correct applications Rigid construction results in an Easy glide for Chairs with casters Lightly textured top surface for added control Gripper back for use on low and standard pile carpet to 3/8"