Second Skin Damplifier Pro Door Pack Butyl Rubber Sound Deadening Vibration Sheets for Cars - 8 Sheets, 13.5 Sq Ft. (12" X 20" X 2 mm) - Made in The USA Increase the volume of your music by keeping the acoustical energy inside of the vehicle. Excellent for use on automobile door skins, floors, ceilings, trunks, and in between rattling panels. Damplifier Pro is a constrained layer damper that converts vibration energy into low level heat. This conversion of energy makes it 300% more efficient than tar boards and asphalt mats while weighing half as much. Directions: Cut, peel & stick to any prepared fiberglass, aluminum or sheet metal. Thermal range of -75F(-60C) to 450F(232C) preventing melting or falling off. Proudly Made in the USA.