This unit is a high pressure pump with 35 US Gallons per minute volume, and a maximum pressure of 700 PSI. It is a four-diaphragm pump with stainless steel valves and seats. When this pump option is chosen we us a chain drive on the offset to reduce the RPM’S of the pump down to 450 RPM, again this effectively reduces the volume to 29 US Gallons per minute from this pump as we set it up. The chain is utilized because at high pressures the horsepower requirements would exceed what a belt could accommodate. With this option we upgrade the electric valves to 600-PSI high-pressure electric valves to accommodate the potential operating pressures. This upgrade is included in the optional price for the pump.