DIGITEN 3/8" Water Pressure Gauge Meter 0-1.6MPa 0-220psi for Reverse Osmosis System Pump &iexcl;&shy; Pressure range:0-1.6MPa or 0-220PSI Diameter of gauge:2" 3/8" Quick connect fitting. Easy to hookup, Connector material is PE, and gauge material is stainless steel. Monitor the post R.O. water pressure and vital to the functionality of your RO system!