Spend less time centering your target and more time stargazing with Celestron's StarPointer Pro. It was designed to provide the easiest experience locating celestial objects in the night sky by projecting a dual circle reticle to allow you to find your object without obstructing it. The circles also serve as a measuring tool while starhopping. For added convenience, StarPointer Pro features a 40 mm optical window with a large field of view. The StarPointer Pro has a rheostat to control the reticle brightness and attaches quickly to most telescopes with a dovetail connection and finger knobs.