The Bushnell(r) Northstar(r) 90mm Makstov telescope utilizes a spherically curved front lens element in conjunction with a similarly curved primary mirror for sharp images in a compact, fold-light path package. The computer-driven location and tracking capability features a built-in data base of 20,000 celestial objects. You simply call up your target on the hand-held conrol module and enter a simple "Go To" command.