The Farpoint Astro Primary Mirror Center Marking Kit aids in collimating your reflector telescope. Using your laser & Cheshire and the included center marking template you'll be able to accurately place one of the eight included marking triangles that will help you align your primary and secondary mirrors during your collimation process. The other triangles can be used on other telescopes or when you need to collimate again. This kit includes the template and triangles, you'll need to provide the laser and Cheshire.