The Telrad sight is a non-magnifying sight to make star-hopping fun and easy. After a simple alignment process to ensure that it is perfectly lined up with your telescope and finderscope, the Telrad's intuitive "heads-up-display" of a lighted red reticle allows you to simply look through the glass window to see what the telescope is looking at.When you point the Telrad at any object in the night sky (for example, a prominent star like Polaris or Vega) you know the telescope's eyepiece will be centered on that same object.
Then as you explore the sky you can use the Telrad to help you find fainter Deep Sky Objects by referring to star charts that include the Telrad reticle printed to scale. The outer circle in the lighted red reticle covers 4 degrees of the sky, the middle circle covers 2 degrees, and the small inner circle covers 1/2 degree. And the built-in variable switch allows you to easily reduce the brightness of the projected reticle when looking at fainter stars or increase brightness for brighter objects.
Requires 2 AA batteries (not included).