Re-Designed and Improved heavy duty Honda CB900C CB 900C Custom Supersport Regulator Rectifier has a higher power handling ability than the original OEM part. This regulator rectifier comes with a direct plug in connector. This unit is much more efficient than the OEM regulator rectifier because of its improve cooling fin design which allows it to dissipate heat quickly & effectively.

These are some of the several OEM numbers that this part would fit:
OEM Part Number(s) 31600-MA1-008