Exhaust Muffler, Air Inlet Size 1 1/2 in, Air Inlet Type NPT, Maximum Flow Rate 200 cfm, Filter Element Material Borosilicate Cloth, Maximum Operating Pressure 12 psi, Minimum Operating Temperature 36 Degrees F, Maximum Operating Temperature 122 Degrees F, Noise Reduction Rating 25 dBA, Filter Efficiency Rating 99.9 Percent, Filter Media Borosilicate Cloth; PVC Fiber, For Fluid Type Exhaust Air, Material Filtered Oil, Number of Air Inlets 1, Outside Diameter 3 7/16 in