White Butyl Sound Deadening Mats For Cars , Noise Isolation With Black Closed - Cell FoamTriple parts products: 3 effects1. Viscoelastic absorptionabsorbs the metallic resonance of the door2. Aluminumless more road noise3. Acoustic foamcancels the harmonic distortions by the absorption of a part of the back wave WanTai sandwich sound deadening is made up of three layers, 1.5mm thickness butyl and 0.05mm thickness aluminum and 4mm thickness acoustic foam. it can attenuate the low frequency greatly and isolate the vibration from the road and the engine. Use for floor, door, trunk, stereo enclosures, under dash, inner firewall and etcEasy-to-install, very high-strengthadhesive butyl rubberEliminate bodyfloor vibrationBetter audio sound quality