"The Dynamic Fluid Components hi/lo hydraulic gear pump provides max. pressure of 900 PSI for low pressure and 3000 PSI for high pressure, making it an ideal choice for log splitters, presses and similar equipment requiring rapid movement of the cylinder at low pressure prior to switching to the high pressure mode to meet load requirements. Shaft Diameter in. 1/2, GPM 16, Stage 2, Max. PSI 900/3,000, Rotations Per Minute 3,600. 16 GPM 1/2in. shaft 1in. inlet 1/2in. NPT outlet 400/900 PSI @ 3600 RPM in low mode 3000 PSI in high mode Hi/lo section is all aluminum"