Electric Machinery Gear Motor Variable Speed Reduction Controller 135 RPM 1:10. Gear motor electric motor 1. Our products are divided into two packages. If you are short of one package for the time being, please contact our customer service to check whether another package is on the way.Geared motor size: 139MM 90MM 74MM. Under different deceleration ratio, the output shaft speed is different. The output shaft speed is equal to the motor speed of 1. 0 rpm divided by the deceleration ratio.