Outfitted with both M68 and M60 male mounting threads, the Alpine Astronomical Baader Ultra-Short 2" Eyepiece Holder is designed to fit a wide variety of focusers, including all SteelTrack and 3.5" Hyperion, while providing a short back focus distance.
When using the M68 mounting threads the back focus distance is 12.4mm, and 17.4mm with the M60 threads. Designed to accept standard 2" eyepieces and accessories like diagonals, the holder has three thumbscrews that allow the eyepiece to be properly centered and to resist canting or tilting. The internal brass compression ring ensures the eyepiece's nosepiece won't get marked or marred.
A ring on the eyepiece-side of the holder is removable to reveal M68 male threads. These threads allow you to mount M68 extension tubes and rings to work as a 2" eyepiece holder for eyepiece projection astrophotography techniques, to accommodate the Fluorite Flat-Field Converter into the beam of light, or to mount a Telecentric System.