Designed for calibrating reflecting telescopes; SVBONY laser collimator allows anyone easily collimate 1.25'' and 2'' reflector telescopes; come with removable 2" adapter; built with metal material; make alignment no longer boring and time consuming Easy to use;accurate collimation in a few minutes provide a more clearer image;no longer have to go back forth;just watch the collimator from the mirror end of the scope and adjust the screws 7 brightness levels red laser beam;adjustable brightness;suit for different light conditions;amazing alignment in dark and day;so can get the better views possible from your reflector telescope Solid metal body;for a long term use; comes with a full set of instructions with a step by step procedure on how to properly align a relfecting telescope Triple cemented of Lens;Improve the stability of red dot;Red laser with 7 brightness levels;Quick alignment;much faster than a manual collimator ; It's a great Halloween birthday christmas gift This collimator comes with a 2" adapter; when you upgrade your 1.25" telescope to a 2" telescope; you do not need an additional 2" calibrator that can calibrate the 2" telescope