Characteristics: It mainly fits do series Celestron 80EQ SE SLT PS and astronomical telescopes series meade infinity and polaris etc. A simple, affordable and effective do collimator sight device aimed at your telescope. They have variable brightness levels, fully adjustable up and down, left and right. The LED dot is projected onto a non-enlarging observation window, so you can quickly and easily aim the main telescope. The top of the Red Dot finder can be removed and used as a replacement for many other Red Dot finders found in telescopes. . Red Dot Scope Viewfinder Star Finder do telescope . Red Dot Scope Viewfinder Star Finder do telescope Specification: They allow installation with hole distances from 5/8 do 1 inch approx. Black color Material: plastic; Battery: CR2032 button battery, but not included Dimension: Approx. 115*70*40mm/4.5*2.8*1.6in Weight: Approx. 40g Usage:Electric light fired into the lens showing red dots, using three do determine the principle of a straight line to find stars. . Red Dot Scope Viewfinder Star Finder do telescope . Red Dot Scope Viewfinder Star Finder do telescope List of packages: 1 * red dot sight; . Red Dot Scope Viewfinder Star Finder do telescope . Red Dot Scope Viewfinder Star Finder do telescope