Pumps come with cast iron sleeve and enough CFM to power most tools used on construction sites. Efficient compact design.CFM displacement - 16.913.3 CFM @ 90 PSIMaximum PSI - 170 PSIRated for 3 HP at 1450 RPM (170 PSI Max.), 4HP at 1450 RPM (130 PSI Max.)Bore: 2.36in., Stroke: 2.28in.Single stageTwo cylinderCast iron sleevePump rotates CCW as viewed from the flywheelUses one A groove beltOil sight glass13in. diameter flywheel/fan