The Telrad finder is the best-selling non-magnifying finder for Dobsonians, equatorial reflectors, refractors, and Schmidt-Cassegrain telescopes.
The Telrad projects a series of concentric red rings (4 degrees, 2 degrees, and one-half degree in diameter) on a tilted clear viewing plate at the top of the finder. These circles make it easy to starhop from object to object.
If a galaxy is 10 degrees north of a known star, for example, two 4 degree Telrad jumps and one 2 degree jump from the known star will take you to that galaxy in seconds.
The half-degree circle makes it easy to quickly center a computerized scope on guide stars for start-up alignment, and to center on planets, comets, and deep space objects if you’re scanning the sky manually. The red circles can be seen from virtually any distance behind the Telrad, from two inches to two feet, so eyeglass-wearers can easily use the finder.
Collimating knobs at the back of the Telrad allow you to line up the finder with your main scope optics. An on/off switch and integral rotary brightness control allow you to match the finder brightness to your eye’s dark adaptation. The Telrad uses two 1.5V AA batteries.
Attaching the finder to your telescope is extremely simple
This well respected telescope add-on is ready to attach to your scope using the universal supplied base plate via screw holes or sticky pads.
Certainly there are many amateur astronomers who consider the Telrad finder a "must-have" accessory, as it makes quick and easy work of locating and finding objects in the night sky.