Utilizing our reversible flexible impeller pump technology, ballast systems can be filled or emptied. Available with or without Reversing Polarity Switch to fill or empty ballast tanks. Includes run-dry impeller. Complies with USCG 183.410 and ISO 8846 MARINE (Ignition Protected). 1″ (25mm) hose barb or 1/2″ NPT internal port.Includes Mastercraft OEM Connector, No Reversing Switch.NOT TO BE USED IN POTABLE WATER SYSTEMS.