Compact size Tough, cellular, sintered Bronze structure, secured to metal body, ensures desired combination of filtering and mufflering with adjustable flow The adjustable tapered metering valve provides a fine adjustment of air flow, for pressure applications and for vacuum relief on vacuum systems External adjustment screw accurately varies orifice opening from closed to full flow as required. Securely locked at the desired setting with a locknut, it cannot be accidentally tampered with, removed, or blown out Filtration element: 40 micron Benefits: Speed Control Mufflers provide an infinite variation of metering air flow with complete safety at an acceptable sound level on exhaust ports of air valves.