Sierra's 18-5775 Switch Box fits 3 and 6-cylinder outboards with ADI ignition systems. It is interchangeable with CDI 114-7778, Chrysler/Force/US Marine 332-7778A12, Mallory 9-25100, Mercury Marine 332-5524A1, 332-7778A1, 332-7778A12, 332-7778A3, 332-7778A6, 332-7778A7, 332-7778A9, F749301, F7778A9, Mercury Race Outboard 332-7778A12, 332-7778A3, and Mercury Sport Jet 332-7778A12. Each Sierra product meets or exceeds the original equipment part it replaces.