Tamiya 89916 4-Speed Crank-Axle Gearbox Kit - Clear

This gearbox has four possible gear ratios, including the highest gear ratio of Tamiya’s gearbox series, 5402:1. The other options are 126:1, 441:1, and 1543:1. This gearbox also features a worm gear, which locks the output shaft when the motor is not turning.