This 143:1 gear motor is much like the GM2 gear motor but runs at nearly twice the speed.

Great for robots needing speed over torque! With a 7mm double flat output shaft (avoid using the green double flat output it's not meant to take rotational load), and a built in clutch and built in mounting screw holes, you can see why we like these motors

These units have an overall size of 55mm x 48mm x 23mm thick and weighs in at 32g.