ASRT IP66-rated, direct-drive, sealed rotary stage provides precise angular positioning in hostile environments. Dual large-diameter bearings control tilt-error motion (3 arc sec), moment stiffness, and repeatability (1 arc sec). Maximum rotary speeds are 100–200 rpm, and the unit uses a brushless, slotless motor, so there are no brushes to wear, no gear trains to maintain and high acceleration and high speeds.