Orion 3640 Collimating Telescope Eyepiece
Economical collimation tool ensures that your reflector telescope's optics are in precise alignment. Combination 5" long sight tube and 1.25" Cheshire eyepiece. For aligning optics of Newtonian reflectors, Dobsonian reflectors, and Schmidt-Cassegrain Telescopes (SCTs). Peephole in top and crosshairs at bottom enable precise optical centering. Compatible with 1.25" telescope focusers or 2" focusers with a step-down adapter for using 1.25" accessories