A followspot aiming accessory, originally created for telescopes. Company Seven | Telrad, Inc. Telrad Sight for Telescopes. One source: TELRAD Telescope Reflex Sight with Mounting Base - Telescope Accessories at Telescopes. Users endlessly argue over which is better, Telrad or SpotDot, much the same way as Leatherman vs. Gerber, or PC vs. Mac. See this thread: http://www.controlbooth.com/forums/lighting/4018-followspot-aiming-tips.html.