M+A Matting 421 Nitrile Rubber Hog Heaven Anti-Fatigue Mat with Black Border, 12' Length x 3' Width x 5/8" Thick, For Dry Areas Outstanding anti-fatigue qualities Solid nitrile rubber top surface for excellent chemical resistance Closed-cell nitrile/PVC cushion backing provides long lasting comfort 100 percent nitrile rubber border remains flexible for the life of the mat and will not crack or curl Certified slip-resistant by the National Floor Safety Institute