Built by Gieseler electronics (Orion Telescopes), model 2118, sn#2543. Accutrack Telescope Drive Speed Control. VG to EX condition. Tracks at lunar, solar, sidereal and automatic rates. Inputs for automatic tracker, declination drive motor, led illuminator, 12 volt dc power input and declination reversal. All cables and connectors included. No manual. All serious offers considered. See photos.