B65427 Porto-Power 10,000 PSI Air Foot Operated Pump 122 Cu.In. Reservoir: With a maximum working pressure of 10,000 psi and its greater oil capacity to handle bigger jobs. The high strength lightweight aluminum reservoir is corrosion resistant and equipped with a pressure relief valve for overload protection. This unit is ready to go to work on all of the jobs, large or small. It has three-positions to provide cylinder advance, cylinder hold and cylinder retract, with a suggested air pressure of 90 - 175 psi and and air exhaust muffler for quieter operation.