The ProTecta Bed Mat is made of Nyracord, cord-enhanced rubber compound that wont crack or break regardless of outdoor elements. The ProTecta bed mats raised knobby underside promotes aeration and drainage to help prevent rust and mildew and also helps hold your bed mat in place. At 3/8 thick the ProTecta bed mat is thicker than all of the rest and their limited lifetime warranty proves it. ProTecta Heavy Weight Bed Mats are custom molded for most vehicle applications.