Pressuretrol Controller, 5-50 PSI Operating Pressure Range, 6-14 PSI Differential Pressure, Snap Switch Makes R-W 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