Product Features Four 12" x 36" Pieces of Sound Dampening Material. 91mil thick (2. 3mm)! There are cheaper, inferior solutions at 50-80mil, but we do not recommend that thin of a solution as it will not perform as well. 12 Square feet total. Made from 100% Butyl Rubber. Eliminates road noise. Quiets vibrations. Increases sound quality and output of car audio system. Stops rattles. Increases SPL. Reduces heat. Easy to form aluminum conforms to desired area of vehicle with ease. Four step peel and stick design for easy installation. Up to 30% thicker than the leading competitors. Dimensions (each piece): 12" L x 36" W. Authorized Internet Dealer. 1-year Manufacturer's warranty.