Caption says it all, this prime-focus unit besides setting the perfect focal point for focus also can be used to check focal plane errors and misalighnment of the optical axis. This unit is compatible with all telescopes via a T-thread, the same adapter that also accepts a T-ring which connects a camera. Includes instructions. Unit was hardly used and is like new condition basicly. Asking $70 shipped in continental USA. Sorry, have no pics, my digital camera was destroyed in a canoe spill.
I accept paypal W/ no extra charges, M/O, and ckh. Thanks, Dave