Adjustable speed belt gear motors are space-saving, consistently adjustable drives. In the typical version the central adjustment is manufactured with a hand wheel. Unlike inverter operation the motor power remains constant and the torque raises if the swiftness of the motor drops.
The variable speed gear unit Variable Speed Belt Gear Motors Speed Reducer Gearbox housing has a confirmed symmetrical design. The adjusting pulleys possess a wedge formed symmetrical cross section with low mass. The shape of the pulleys ensures uniform flank pressure and for that reason high power transmission, even at high belt rate.
The result is 
optimal control behaviour with uniform distribution of forces and minimal energy consumption.