This is a triplex (three plunger rods) positive displacement, reciprocating, plunger pump, constructed of a special W770 manifold, 304SS valve assemblies, solid ceramic plungers and standard NBR (Buna-N) seals and o-rings. Technical Specifications Max Flow 4 gpm / 15.1 lpm Max Pressure 2500 Inlet Port Size 1/2" NPT(F) Discharge Port Size 3/8" NPT(F) RPM 950 Drive Type(s) Belt, Clutch, Flexible Coupling and Bellhousing Material Brass