More on Amazon.com : http://www.amazon.com/gp/product/B0069VXKM4?tag=thefatkidin06-20 <br /> <br />Orion 3640 Collimating Telescope Eyepiece <br /> <br />Economical collimation tool ensures that your reflector telescopes optics are in precise alignment <br />Combination 5 long sight tube and 1 <br />25 Cheshire eyepiece <br />For aligning optics of Newtonian reflectors Dobsonian reflectors and Schmidt-Cassegrain Telescopes SCTs
