Orion 7947 Atlas/Sirius Computerized GoTo Hand Controller Equips your StarBlast AutoTracker Altazimuth Mount, Atlas EQ-G Mount, or Sirius EQ-G Mount with a database of over 42,000 celestial objects including galaxies, nebulas, star clusters, double-stars, variable-stars, and more A great upgrade for those who originally purchased the Atlas EQ-G or Sirius EQ-G telescope mounts with a Dual-Axis hand controller or with a non-upgradable hand controller Tour button on computerized controller takes you on a preset tour of the best night sky objects visible through a telescope on a given night Includes bracket for attachment of controller to tripod accessory tray, RS-232 computer interface cable, wire clips, and two mount attachment cables Computerized controller features sync function and internet upgradeability