This Cheshire collimator is designed for a reflector telescope that incorporates a standard 1 1/4" focuser and eyepieces. This scope accessory offers "one piece" construction, allowing quick and precise alignment of the primary and secondary mirrors of the reflector.

Our unique cross-hair center hole makes perfectly centering the lens dot much easier. A distance of 5" from peephole to cross-hairs gives a much better sight radius than most collimators, allowing for the higher precision.

This tool is made to fit snugly in the focuser for the most accurate mirror alignment possible. But with manufacturing tolerances of different scopes being an unknown, slight fine sanding of the outer barrel of this collimator that rests in the focuser might be needed, should the fit be just a little too snug. While very durable, this material will sand evenly and easily, and not mar the focuser or this product.

To read an explanation, in easy to understand terms, of how collimators can be used to align a telescope, please visit this great site: A Beginner's Guide to Collimation.

If your scope uses a 2" focuser/eyepieces, or the older model scopes using a .965 inch focuser/eyepieces, or if there is any other modification of the stock collimator needed, please don't hesitate to ask.