This sale is for a really excellent condition Mamiya 645 Polaroid Back Adapter. The only signs of use are some missing paint along one side of the adapter.
This adapter allows you to use a Polaroid back on your Mamiya 645 Super, Pro and Pro TL cameras and still be able to mount the camera on a tripod.
Normally you cannot put a 645 with Polaroid back on a tripod because the back extends down below the bottom of the camera and simply gets in the way of the tripod head. With this space fitted, this lifts the camera enough that the problem simply disappears.
Also usable with Bronica ETR series cameras (and maybe others) that have exactly the same problem.