With this Vixen Optics 100mm Finder Eyepiece you can eliminate the need for a conventional finderscope to make finding and viewing celestial objects faster and easier. Its extremely long 100mm focal length yields very low magnifications on even the largest catadioptrics or longest refractors, and the wide 11° apparent angle of view makes finding your target object easy as long as you're in the right general area of the night sky. Centering your subject is made even more convenient with the crosshair aiming reticle. This Finder Eyepiece is outfitted with a 1.25" barrel to fit the most popular size drawtubes, visual backs, and diagonals.