Aobi Universal Telescope Eyepiece Alignment 1.25"/2'' Laser Collimator LK1 for Newtonian Telescopes Imported CNC High Quality Aluminum&Metal material, Stable and Durable Red laser collimation beam with 7 brightness levels Can fit into 1.25" focusers or diagonals,With Removable 2" adapter Wavelength 635-655 nm;Output power adjustable: 1mw - 5mw, much safer for your eyes CR2032 Lithium Cell battery ;7*24 hours customer service,please buy with confidence:)