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. The Type 260 motor has been used in a variety of applications since its release in 1985. The gearboxes are often used in Robotics contests and enable the possibility of assembly with high and low gear ratios.
Specifications:

Gear Ratio: 1428.2:1

RPM: 7
Torque g/cm: (2.306)

Gear Ratio: 555.4:1
RPM:18
Torque g/cm: (2.306)

Gear Ratio: 216:1
RPM: 47
Torque g/cm: 2851

Gear Ratio: 84:1
RPM: 120
Torque g/cm: 1071