The Nu-Calgon Refrigeration Oil Pump provides for the addition or removal of refrigeration oil when servicing air conditioning and refrigeration systems. The pump can be used while the unit is operating. It is not necessary to shut down the system for charging. Can be used on one gallon, two and a half gallon and five gallon containers. Moves 2.6 fl. oz. (78 ml) per stroke against 200 psi pressure. Fitting and transfer hose included. Use with all oils.