The Telrad is a very innovative finder and an attractive alternative to a regular finderscope. It is particularly easy to use and you still see the full sky in front of your eyes, not just a small part of the sky. The Telrad can be used almost on any telescope: it comes with a universal quick release base which you can mount on almost any telescope.
The Telrad projects three rings (0.5°, 2° and 4°) onto a glass window. You look at the night sky through this window and you will see the unchanged sky, but with these three rings "hovering" in front of the stars.