noise insulation sponge foam ear plugs/invisible ear plugs

featureSound-absorbing effect is good,functionFR,Rohs,svhcUsesNoise reductionIndustry StandardGB,BS-5852 or TB117 when the sound waves incident into it, it can cause gaps in the air vibration; the viscous drag due to air friction and pore walls, so that a considerable part of the sound energy into heat energy has been consumed.