Face NUBS are reinforced with rubber to resist crushing, maintaining high performance and extending product life Border is designed to hold water and dirt on mat to minimize slip hazards and floor damage around perimeter of the mat Removes and traps dirt and moisture and holds it on mat below shoe level so it is not tracked in Gripping action minimizes movement on most carpets and improves traction on hard surfaces Lays flat, won't crack or curl like vinyl mats