The Skywatcher 1mW Red Light Laser Collimator for Telescopes contains the best and most important features that such a tool needs. A large viewing window allows the user to easily view the collimation surface. While most other lasers only have one brightness setting, this one offers 7 different brightnesses depending on the application. The 1.25″ laser collimator comes complete with a 2″ adapter to be able to use it in all focusers. It was developed to precisely collimate Newtonian telescopes, Dobsonians and refractors. Scope of delivery: 1.25″ red light laser collimator 2″ adapter! Power supply and batteries are not included!