Add right ascension (RA) tracking capabilities to Celestron Astro Master & Power Seeker equatorial telescopes. This easy-to-install RA motor drive compensates for the Earth's rotation, so the telescope tracks a star's movement through the night sky from east to west. When the telescope mount is properly polar-aligned & the RA drive is attached & running, you only need to make occasional adjustments in declination (Dec) to keep an object in the eyepiece for long periods of time.