Generic Pneumatic Sintered Bronze Air Breather Vent Muffler 1/4" Male NPT Brass Silencer Fitting (Pack of 5) Materies:base,brass(muffling element, sintered bronze) . Net Weight: 11.72g/pc. Thread: 1/4" Male NPT. Working Pressure: 0-116 PSI. Working temperature: from -10 to +70 ?C.