Curtis-Toledo offers the MASTERLINE CR-25 Series air compressors for those heavy-duty industrial applications. This line of low-speed, cast iron 1-30HP, single and two stage, up to 250 PSI air compressors is pressure lubricated. With Curtis' centro-ring oiling system, pressurized oil is supplied internally through a rifle-drilled crankshaft and rods to all bearings, bushings, and wearing surfaces for extended pump life.