The size of this gearbox is 60 x 60mm and the input shaft diameter is 10mm. This high-precision planetary gearbox is belong to EG series gearbox, it with gear ratio 20:1 and a maximum 20arc-min backlash. It's an excellent choice for applications that require good accuracy and reliability at an exceptional value. This inline planetary gearbox built-in an input shaft coupling which can match any standard 10mm diameter shaft of Nema 23 stepper motor and brushless dc motor.