The motor gearbox assembly uses a DC motor with worm and wheel drive mechanism designed to greatly increase the available torque produced by the motor. Although this is still very much a light duty arrangement it makes it much more usable for the robotics enthusiast than a simple DC motor which tends to have too little torque and too much speed. The motor is rated for 1.0 - 6.0v

Basic Specifications
At 6v operating voltage
speed no load 17,100rpm
Motor stall torque 220g-cm
Gearbox ratio 42:01:00
Axle diameter 3mm Axle length 125mm
Fixing holes 4 x 4mm
Overall dimensions of box + motor 35(W) x 40(H) x 60(L)mm