Orion StarSeeker IV 102mm GoTo Mak-Cass Telescope This 4" diameter GoTo Mak-Cass boasts a very long 1300mm focal length and f/12.7 focal ratio, for sharp and detailed high-power views of the Moon, planets, and brighter deep-sky objects Huge GoTo database of over 42,000 objects, and handy built-in Tour mode means you'll enjoy great views on any clear night Once aligned, dual optical encoders on both axes of motion allow manual aiming of the telescope without losing GoTo alignment After an object is selected, the StarSeeker IV 102mm locates and tracks it automatically so you can relax and enjoy the view Includes GoTo hand controller, 23mm (57x) and 10mm (130x) wide-field 60-degree eyepieces, 90-degree diagonal, EZ Finder II sight, and more