Amazon Basics car soundproofing sheet, size 37 x 25cm. I purchased 10 sheets and used 4 for deadening, so there are 6 sheets remaining. The 6 sheets are new and unused. The instruction manual has some stains. Product Description Car soundproofing material (10 pieces). Provides a quieter and more comfortable car interior environment. The soundproofing material (butyl rubber compound base substrate) reduces annoying vibrations and noise from the car and road. Strong self-adhesive backing for secure attachment. The front side also has reflective aluminum foil, providing excellent insulation. Flexible material that can be easily cut and installed in the car interior, cabin floor, and trunk. An instruction manual is included in the installation kit (may not be in Japanese).