Celestron Advanced VX Computerized Mount. The Celestron Advanced VX Computerized Mount was specifically designed to provide optimum imaging performance for smaller telescopes. The integer gear ratios and permanently programmable Periodic Error Correction eliminates recurring track errors from the worm gear. The new motors offer improved tracking performance and provide more power to overcome load imbalances. It has All-Star Polar Alignment technology which features a Two-Star alignment mode that draws upon a vast database of stellar bodies to choose multiple guide stars that assist in tracking across the night sky while keeping the optical tube parallel to the Earth s axis of rotation. The 91519 has an updated industrial design that offers more rigidity less flexure and improved aesthetics. Its new design allows viewing or imaging across the meridian without interference from the motors housings. The Nexstar+ hand control offers multiple language programming.