The Model 22S/GM Series dc servo "true planetary" gearhead is about half the length of most conventional gearbox designs in the same frame size and ratio. It typically puts out only 50 to 60 dB of noise, compared to >85 dB that is typical of conventional gearhead designs. The 22S/GM, from Dynetic Systems Corp., Elk River, Minn., sells for less than $100 per stage, including the motor, at the 100-unit level. Its gear meshing is such that no-load current draw is about a third of what is typically required to turn ordinary gearboxes. Little torque is wasted turning the gears, resulting in a system that runs smoothly and efficiently.