- 2 pezzi in confezione scatola 4 pezzi in confezione scatola AERO-Butyl Butyl and aluminum constrained layer damping material. Designed for damping metal or plastics and reducing unwanted structural vibration, rattles and sound from inside or outside of your car. High efficiency to convert vibration to thermal energy. Highly adhesive and easily conform to irregular surfaces like door panels or roof interior. Water resistant and hardly inflammable.