PneumaticPlus RM Series Resin (Polyethylene) Muffler/ Silenicer, 5 Micron Polyvinyl Foam, Pack of 10 (3/8" NPT) Rigged Polyethylene Housing with Polyvinyl Foam Element (5 Micron) Compact muffler is furnished with standard Male 3/8" NPt (Pack of 10) Used to diffuse air and muffle noise from exhaust port of air valve, air cylinder & air tools Max Operating Pressure: 130 PSI/ Max Operating Temp: 41F to 140F