Battery-operated or portable equipment where supply current may be limited are good examples to use a gear reduction. In-line and offset versions are available in a wide range of ratios. The design of a planetary gearbox enables a high ratio to be utilized in a single stage with the result that torque transmission is maximized and gearbox size minimized.

Therefore, planetary gearboxes really come into their own when the requirements are highest rated torque in the smallest package.