GRIPPER BACK for use on low pile carpet measured up to 1/4in thick PRODUCT DETAILS: chair mat, 36in x 48in with lip, 2.16 mm thickness, 5.8 lbs Flat packed inside a box for easy transportation and handling, smooth surface with fine texture for chair to roll easily without skidding, clear mat lets color of the carpet shine through ODOR FREE & NONTOXIC PVC: Tested BPA and Phthalate free, recommended for indoor use in places such as offices, schools, and healthcare facilities NO QUESTIONS ASKED GUARANTEE: Before using mat, test with foot to ensure it doesn't move. We are proud to offer our customers a no questions asked guarantee on your purchase. If you are unhappy with your chair mat, contact us directly . We want you to enjoy our products as us!