Powerhobby 12T 30T Gearbox Belt Drive Gear Set Black FOR Traxxas TRX-4 TRX-6 PHB5346Black

The main gear is 12t, the driven gear is 30t, with non-destructive mounting screws, which greatly reduces the original noise and flexibility

Due to the narrow space, you need to preset the active gear into the pulley, and finally put in the motor gear output