AIR COMPRESSOR PUMP, LUBRICATION TYPE SPLASH LUBRICATED, NUMBER OF STAGES 2, MAXIMUM OUTPUT POWER 15 HP, FREE AIR FLOW RATE @ MAXIMUM PRESSURE 51.0 CFM @ 175 PSI, NUMBER OF CYLINDERS 4, MAXIMUM OPERATING PRESSURE 175 PSI, FLYWHEEL DIAMETER 19 3/8 IN, FLYWHEEL INCLUDED YES, PUMP SPEED 1,020 RPM, CONSTRUCTION CAST IRON, VALVE MATERIAL STAINLESS STEEL, ROTATION CCW, STROKE LENGTH 3 IN