Specification: Total Size: 30 * 30 * 5cm (12"*12"*2") Thickness: bottom 1.5cm， slot height 3.5cm Material: Polyurethane foam Color: Black Feature: Using polyurethane foam material. After special treatment device side triangular groove shape formed by the complex process of foaming silencer， sound-absorbing， sound insulation， shock absorption sponge materials. Its interior is full of small voids and semi-open pore structure can absorb a lot of energy incident on the acoustic attenuation of sound waves play a role， reducing chamber reflected sound interference and response， improve the purity of sound; noise sound-absorbing material is a high-performance product.Application: * Family noise control (walls， pipes， ceilings， etc.) * entertainment noise control (KTV rooms， walls， ceilings， floors， etc.) * workplace noise control (light walls， partitions， conference rooms， etc.) * Industrial noise control (factory walls， roofs， equipment， doors， control room， etc.) Package included￡o 5 x Charcoal Acoustic Wedge Foam "Dear buyer，when you received your parcel，the sponge may have a different with what we described on our listing.Please do not worry，Coz we compressed the sponge，when packed and as there is a long time of compression，the sponge may have a little difference and it may need a few times to restore.And because the sponge is too large to pack，without compression，we can not send them out.Wish you can understand.When you received it，please open the parcel and take them out，leaving them for a few days，they will restore soon.And if some corner still sunken，you just need to pull it with small force，it will restore soon as well."