Tamiya 72008 4-Speed Worm Gearbox Kit The Tamiya 72008 4-Speed Worm Gearbox kit includes one brushed DC motor and all the gears and parts to build any of the four possible gear ratio configurations: 84:1, 216:1, 555.4:1, 1428.2:1 . The four gear ratio options give you the flexibility to choose the best speed and torque for your project. Tamiya 72008 4-Speed Worm Gearbox Kit The kit includes step-by-step illustrated instructions in both Japanese and English. A scanned copy of the instructions is available on the Pictures tab. The kit can be built with just a screwdriver, but the instructions recommend having side cutters, pliers, and a modeling knife on hand. Complementary products This gearbox has a 4 mm diameter, round output shaft, which works with the wheels that are compatible with Tamiya 4 mm, round shafts and our 4 mm universal mounting hub. Our 3 mm universal mounting hub also fits on the smaller threaded end of the shaft, although it is not specifically intended to work with this type of shaft (the hubs set screw could damage the thread on the shaft). The low-voltage motor in this gearbox runs on 1.5-4.5 volts and draws up to a few amps when stalled, making it compatible with our DRV8833 motor driver carrier if appropriate precautions are taken to avoid stalling the motor. The mounting holes on the gearbox are compatible with the Tamiya 70098 universal plate set and other Tamiya construction series products. Features One type 260 motor. For motor specs, see the Mabuchi motor RE-260 ( 2295) data sheet (59k pdf). Four different gear ratios: 84:1 216:1 555.4:1 1428.2:1 Worm gear (locks the output shaft when the motor is not turning)4 mm round output shaft (length: 100 mm) compatible with Tamiya wheels for 4 mm, round shafts and our 4 mm universal mounting hub. Assorted cranks Note: The Tamiya 72008 4-Speed Worm Gearbox is a kit assembly is required. Documentation on producer website.