auto muffler can reduce the noise, and refuse the dusty,oil,air or anyother materials which can't work with the equipments syste A Type Series auto MufflerMaterial:BronzeItem Code:-M5A,-6A,-8A,-10A,-15A,-20A,-25AThread Size:M5,1/8",1/4",3/8",1/2",3/4",1"Thread Kind:BSPP,BSPT,NPTColor: NatureNormal Package:Plastic Bag A Type Series auto Muffler