Hudson Exchange 4012 Waterhog Classic Boot Tray, 34" L x 15" W, 3/8" Thick, Medium Gray Suitable for indoor or outdoor use Unique ridged construction effectively stores dirt and moisture beneath shoe level Exclusive "water dam" border keeps dirt and water in the mat and off the floor, minimizing slip hazards and floor damage Green friendly rubber backing has 20 percent recycled rubber content Exclusive rubber reinforced face nubs prevent pile from crushing in high traffic areas