This is a triplex (three plunger rods) positive displacement, reciprocating, plunger pump, constructed of a forged brass manifold, 304 stainless steel valve assemblies, solid ceramic plungers and standard NBR (Buna-N)o-rings and low pressure seals. High pressure seals are a special blend PTFE for high temperature applications. Technical Specifications Max Flow 4.2 gpm / 15.9 lpm Max Pressure 2200 Inlet Port Size 1/2" NPT(F) Discharge Port Size 3/8" NPT(F) RPM 1725 Drive Type(s) Belt, Clutch, Flexible Coupling and Bellhousing Material Brass