... -friendly 2.soft surface 3.high efficient noise insulation wave sound proof sponge effect is good, function FR,Rohs,svhc Uses ... StandardGB,BS-5852 or TB117MakerDaye Tengfei Sponge/foam when the sound waves incident into it, it can cause gaps in the ... and pore walls, so that a considerable part of the sound energy into heat energy has been consumed. Dear friends, Hello ...