This was designed to hold a ToupTek GPCMOS 1.25" camera on a standard 1/4-20 threaded tripod for testing purposes.

After printing, drop a standard 1/4-20 nut into the hole; superglue it if you feel so inclined.

There is a new version of this design that now includes a dovetail for a low-cost reflex sight such as those from Orion, Astromania, or Celestron.