Material: metal, long service life. Thread size: about 16mm. 【Noise Reduction】This air compressor muffler is used in the intake port of the air compressor. It is a good option to reduce the noise of your compressor and a great aftermarket replacement. 【Blocks Dust】Used for the air compressor inlet, can effectively block the dust in the air humidity. 【Extends Service Life】Helps improve the efficiency and longevity of the air compressor. 【Wide Application】Suitable for air compressors. Oil-free air, can be used in noisy equipment such as fans, air compressors, boilers, outlets, etc. Generators, pumps and exhaust ports.