The MFJ-5124Y interface provides power and control signals between a Yaesu radio and the MFJ automatic tuner.
Supported Yaesu radios are
FT-100D,
FT-450D,
FT-840,
FT-847,
FT-857D,
FT-891,
FT-897/D,
FT-950,
FT-991/A,
FT-DX-101D/MP,
FT-DX-1200,
FT-DX-3000,
and any Yaesu radio that supports the Yaesu FC-20/30/40/50 tuner.