?Friendly to Everyone?This adjustment tool can be used in all 1.25" focusers. We provide you with precise instructions in German and English, with a step-by-step explanation of how to adjust a Newtonian telescope using this laser unit. So, even if you are a newcomer to amateur astronomy, it is very simple to get the optimum performance out of your telescope. ?Well-Engineered?The laser comes fully adjusted. It can however be further adjusted if required. It has three openings for adjustment, arranged at 120°, which are initially sealed. The battery for the laser can be install at any time; the small screw cap at the rear of the laser must be first unscrewed to allow this. ?Practical Design?Red laser collimation beam with 7 brightness levels, wavelength 635-655 nm; Output power: less than 5mw, much safer for your eyes. Only when the optics have been accurately collimated can the telescope offer you its full performance. ?High-Quality and Durable?High-quality metal construction and anodizing aluminium process, durable for long time use. Require one CR2032 lithium battery (Not Included). ?Multi-Function?Designed for Reflector telescope, fit for standard 1.25 inch diameter. This sturdy laser unit allows you to swiftly and precisely collimate your Newtonian telescope. Accurate collimation in a few minutes provide a more clearer image. The telescope can be collimated by just one person.Item Weight: 3 Ounces. Finderscope: Reflex. Power Source: Battery Powered. Product Dimensions: 5.04"D x 1.28"W x 1.28"H. Objective Lens Diameter: 32 months. Brand: Astromania. Manufacturer: Astromania. Date First Available: March 21, 2016. Is Discontinued By Manufacturer: No. Best Sellers Rank: #23 in Telescope Photo Adapters. Customer Reviews: 4.3 out of 5 stars 554 ratings 4.3 out of 5 stars. Item model number: SKU_AM_ZAA1025. : B01D8HMBCQ. Item Weight: 3 ounces. Product Dimensions: 5.04 x 1.28 x 1.28 inches.