THE DAM ON ALL FOUR SIDES OF THIS DURABLE MAT CATCHES WATER ICE AND SNOW BEFORE IT SPREADS ONTO YOUR FLOOR. FOR INDOOR ENTRANCES WITH HEAVY TRAFFIC. GRID-PATTERNED PILE IS MOLDED ONTO RUBBER NUBS. 24 POST-CONSUMER RECYCLED POLYPROPYLENE SURFACE; 25 POST-CONSUMER RECYCLED RUBBER BACK. ICE MELT MAY BE USED ON MAT SURFACE. THICKNESS -1/4"". NFSI CERTIFIED TO BE SLIP RESISTANT.