Expert level sound damping, aluminium outer layer. Highest damping vs weight ratio of any material available Self Adhesive, Easy Installation Expert Roadkill Published Specifications Minimum Thickness 0.08 inch, Minimum Weight 0.65lbs per sq foot Use on all metal panels, doors, roof, floor, firewall and amp, boot Kills panel resoce, squeaks and rattles High-density energy absorbing foam Fits behind interior panels to eliminate interior and exterior noises 12¿ x 24¿ sheets (2 pieces) Increases amplifier output Easy cut and apply installation