Look Into Your Telescope Through an Aline and you see a bright white circle surrounding the image of your eye's pupil, making it easier to center the primary and secondary mirrors, which is especially important for aligning rich field and fast Newtonian and Dobsonian telescopes.
1000's of Alines are in use around the world (yes thousands) since Rigel Systems introduced the first retroreflector collimation eyepiece in 1995. Simple in design, Aline uses an ultra-reflective microprism retroreflector and the light gathered by your telescope to produce a brighter image than "classical" cheshires or even so called "reflective" cheshires (which are retroreflector collimation eyepieces -- not cheshires) that use less reflective microsphere retroreflectors.
