Robinair (15310) VacuMaster Single Stage Vacuum Pump - Single-Stage, 3 CFM Robinair's VacuMaster Single-Stage Vacuum Pump is designed for air conditioning and refrigeration service; featuring a single stage rotary vane design, 8.5 ounce oil capacity, and non-skid feet 3 CFM free air displacement; factory rated to 75 microns 1/4 HP, 110V/60Hz thermally protected motor Features an inlet fitting engineered for maximum airflow, while preventing oil backflow, and finned aluminum surfaces that dissipate heat faster, keeping the pump cooler and extending life 1/4 inch flare and 1/2 inch ACME inlet fittings, easy to read sight glass, easy access oil fill port, and angled oil drain valve for faster, more complete draining of the reservoir