This is an adjustable ball socket wall mount (similar to the SteamVR/Vive Basestation mount) designed for use with the Oculus Rift sensor. It consists of a bottom mount(which screws into your wall), a sphere (printed in two parts) with a screw that fits into that bottom mount, and the top part that screws down onto the bottom mount that will tighten down on the sphere, preventing it from moving once tight enough.
Along with the print itself, you will need 3/4" long, hex head (11mm) screw with a 1/4"-20 thread size (note: this is a standard photography mount thread size.) The screw fits into of the sphere halves and form a single part for the mount. This is the part that the sensor actually attaches to. I also used a small rubber washer to help keep the sensor in place when fully screwed down, but it’s not required.
On my printer, the fit was good but pretty snug. I had to thread the screw partially into the hole and then push it through (I used the other half of the sphere for leverage). The shaft of the screw needs to be able to move through the hole without threading since the head cavity is shaped for the screw and thus you won’t be able to screw it into place.
My plan originally was to glue/epoxy/otherwise adhere both halves of the sphere together but I found that when they were pressed together with the screw inserted, they held together well enough not to need anything else. Once installed in the mount, they can't really move apart anyway.
I also used a 1/4th~ inch square of adhesive backed cork sheet in the bottom mount (as seen one of the pictures) to make for less travel for the upper mount and greater friction against the ball. Depending on your printer this might not be nessesary, but for me it made it fit much more snug.
I printed the sphere halves with supports, but that might not be necessary depending on your printer. The main mount pieces should print fine without any supports.