FLUX PUMP F425 LIQUID-SAVER TUBE SET (less motor): Flux Pump F425 Tube Sets incorporate a backflow prevention lever to allow removal of 99.98% of drum liquid; if drum is tilted then less than 2 ounces of liquid remains. The perfect selection for liquids of high value or high disposal cost. The pump user operates the lever to open and close the backflow valve located at the base of the tube shaft. A mechanical seal protects the inner tube so the pump can not run dry. Easily stripped. Simple robust design means fewer parts for better cleaning and reliability.