A 15-mm direct-driven high-speed rotary stage based on proprietary PILine piezomotor drive technology has been introduced by PI (Physik Instrumente) LP. The MM-660 operates at 720°/s and achieves resolution to 8 arcsec. Its self-locking ceramic drive holds the position steady at rest, with no energy consumption or heat generation. The directly coupled precision optical encoder provides phase lag-free, backlash-free feedback to the servo controller. The compact design with minimized mass and inertia provides high-precision bidirectional speed and position control, and high-speed motion contouring.