What size are small geared motors?

Small geared motors, also known as micro gearboxes or miniature gear reducers, typically include small gear reducers, small planetary gear reducers, small DC gear reducers, and small worm gear reducers. Their outer diameter generally ranges from 3mm to 38mm, voltage from 3 to 24V, and speed ratios from 2 to 2000. They are widely used in smart homes, home appliances, automotive transmission components, industrial automation, electronic products, precision medical devices, infrastructure equipment, robots, and mechanical equipment. Specific specifications and models depend on actual needs, such as required torque, speed, and power.