Zaber's new motorized goniometers (GSM) are stepper motor driven positioning devices with high thrust and speed capabilities. Available in two stackable sizes with 40 or 60 mm centre of rotation, this device has a 30 N load capacity. The GSM has the same footprint and mounting as our original goniometer (LMG), but it has a lower price, more travel, better wiring, a smaller motor for mounting to a flat surface, and the ability to stack easily.