This is a new aftermarket replacement for the CMX400 CBX400 Igniter (CDI) which has been discontinued by Honda.(The new improved part is the orange part below)
The original ignition unit may have been stamped with one of these numbers:
This unit will plug right into your existing wire harness. It may require custom mounting.
This unit has some improvements over the stock unit:
1983 Honda CMX400
1983 Honda CBX400