Jabsco Impellers Neoprene Impeller, 2'' X 7/8'' 5/16'', 4 Drive, Plastic Insert, Blades . Tough, long-lasting replacement impellers from the inventors of the flexible impeller pump. Use neoprene for most water-pumping applications (all are neoprene except those noted in chart) and nitrile for pumping oils and oily water. Impeller inserts are brass or plastic. Click on this Jabsco Impeller Guide for information on selecting, replacing, and troubleshooting Jabsco impellers.