| Number | Name | Brand | Fit |
|---|
| B0213 | Power Pack 900 Futaba Line | Mugen Seiki | direct · Also listed by doc/mugen/mrx-4-part-list |
| B0214 | Power Pack 900 Sanwa Z Line | Mugen Seiki | direct · Also listed by doc/mugen/mrx-4-part-list |
| B0233 | BATTERY CODE FOR R3/B3 | Mugen Seiki | direct · Also listed by doc/mugen/mrx-4-part-list |