... friendly 2.soft surface 3.high efficient noise insulation wave sound proof sponge effect is good, function FR,Rohs ... ,BS-5852 or TB117MakerDaye Tengfei Sponge/foamwhen the sound waves incident into it, it can cause gaps ... walls, so that a considerable part of the sound energy into heat energy has been consumed. Dear ... DetailsUses and product color and packaging requirements wave sound proof sponge