2 pack of TIP125TU-ND transistorsMSx30 Q9 and Q12These are part of the flyback circuit on the V3.0 and V3.57 boards. The V2.2 flyback board also uses these, and it replaces the TIP125 high side driver on the DIYPNP V1.5 board as well.
This is the Bosch BIP373 coil driver triple darlington on its own. If replacing a VB921, you must use a mica insulator. For a BIP373 packaged with a mica insulator, or more information on BIP373s, please see our BIP373 mod kit.