EXAIR's low cost Sintered Bronze Mufflers are easy to install in new and existing exhaust ports of valves, cylinders and other air powered equipment. Each Sintered Bronze Muffler is capable of passing a certain volume of air with minimal back pressure restriction so it doesn’t interfere with the operation of the cylinder or valve. When used with cylinders, the "Muffler Quick Pick" table helps you select the appropriate model based on the actual bore and stroke of the cylinder. (Note: Model 9089 has a 1/2"-20 UNF straight thread to fit most solenoid valves.)