Genuine ISE Spare Part
ISE disposer plug fits into sink outlet to seal water in the sink. Plug used by ISE and numerous other badged makes,  including, In-Sink-Erator, Homark, Badger, Burco, Caple,  MunchMaster, Fobe, Franke, Astracast, Xpelair, Pelican, some KitchenAid ISE made models and certain other makes, etc. 3.5 inch dia size with rubber seal.
Fits ALL ISE continuous feed models from 1966:
Including 45 to 75, and the new range of disposers
Rubber seal is NOT replaceable, only complete plug.