Pressuretrol Controller, 10-150 PSI Operating Pressure Range, 10-22 PSI Differential Pressure, SPDT Snap Action,, Make R-W, Break R-B on Pressure Rise, For Use with Steam, Air, Noncombustible Gases or Non Corrosive Fluids, 120Vac/240Vac, Mount using 1/4"NPT Internal Pipe Threads or Surface Mount Through Base of Glass