This 4-Speed Worm Gearbox H.E. is of the type which is often used at robotics contests and features a low RPM rate for great torque output. There are four gear ratios (84:1, 216:1, 555.4:1, 1428.2：1) to choose from, with the 1428.2:1 ratio offering an RPM of seven times in one minute. The included gearbox attachment parts can be installed at a choice of two positions. A 4mm dia. drive shaft, three kinds of crank arms, and Type 260 motor included. Separately available Type 130 and Type 140 motors are also compatible.