MoonLite Filter Swing Crayford Focuser (Model CR3) is the focuser that any filter nut just has to have. It is the same quality crayford as the Classic Crayford, but with a built-in 2" Swing Filter system. Just screw in your favorite 2" filter, (we are partial to the UHC and O-III), and you can swing it in and out of your view with an above board lever located on the draw tube. Your filter rides along in the bottom of the draw tube so focusing, changing eyepieces, or alternating from clear to filtered view is made quick and easy.