This motor was designed specifically for the MINDSTORMS
NXT set. It has the highest torque of all existing electric
LEGO motors and high power consumption. It includes a
rotation sensor with a one-degree resolution, which is useful
when designing robots that require precise control.
However, its shape and size are a disadvantage when
one is using it outside MINDSTORMS constructions, and it
connects to the power supply through a MINDSTORMS-type
plug, which means that a special converter cable is required
to connect it to regular 9V or Power Functions power supplies.
Unlike other motors, its output is a 3-stud-wide ring
(orange in the figure above) with four 1-stud-deep pin holes
around the center. It also has an empty axle hole in the
center through which any axle longer than 3 studs can be
inserted.