This compact, inexpensive, low-current gearmotor (brushed DC motor with a 180:1 reduction gearbox) is well suited for use in small robots. At 4.5 V, it has a free-run speed of 80 RPM and a stall torque of approximately 30 oz-in (however, the built-in safety clutch might start slipping before the stall torque is reached). The D-shaped output shaft has a diameter of 3 mm. This gearbox output shaft is perpendicular to the motor shaft.