Form factor is a different way of looking at power density. In this context, form factor refers to the physical (primarily dimensional) properties of the motor, which may be defined as the active materials or the overall envelope size. The simplest view of this is the frame size reduction potential of the DEC Star® versus IM…assuming the same power rating. Another way of looking at this is the ability to “down-frame ” the same power rating into a physically smaller package (frame size).