Model originally uploaded to Thingiverse at https://www.thingiverse.com/thing:4378469.
This is an adapter to enable prime focus photography through my Orion XT8 telescope. One side has the Nikon F mount and the other has M60x0.75 threads that fits the focuser on my telescope.
I have a Nikon F mount T adapter and 1.25" T ring that I can attach to the 1.25" eyepiece mount on the telescope focuser, however, using that setup it is impossible to focus properly as there is not enough focuser travel in the direction toward the telescope body. Using a 2X Barlow between the camera and the telescope allows for proper focus, but it adds extra glass into the optics train and the added magnification makes some objects, like the moon for example, too large for a single exposure (at least for my APS-C sensor). My solution is this low profile adapter that mounts the camera as close as possible to the focuser.