16 GPM, 2 stage hydraulic replacement pump for most log splitters on the market today. The 2-stage pump can give you faster cycle times and higher possible pressure with a small engine. Excellent for use on log splitters. 85% efficient. Suggested applications: Presses, Log Splitters, Clamping Units and Compactors Maximum pressure: 4000 PSI Bolt circle: 2.83in. 4 holes spaced 2” on center Mounting hole diameter: .344in. Woodruff key: 1/8in. Rotation is clockwise Flow rates on the hi-low tandem pumps are 0.256 cu in/rev on the low flow and 0.793 cu in/rev on the high flow pump. This 2 stage pump can give you much faster cycle times and higher possible pressures with a small engine. Excellent for use on log splitters. 85% efficient. Model GP-CBN is a HI/LO hydraulic gear pump with 12 different displacement combinations with maximum pressures of 900 psi for the low pressure pump and 3000 psi for the high pressure. The change from LO to HI pressure is automatic with the LO side pressure pre set from 400 psi to 900 psi. The HI/LO section of the pump is all aluminum and the end plates are cast steel. Applications for the HI/LO pump are log splitters, presses etc where rapid movement of the cylinder at low pressure is required prior to automatically switching to the high pressure mode to meet load requirements.