It's a two part clamp that enables you to mount your Shuttle Mini-PC to the stand of your monitor. One part is screwed to the back of the mini-PC, the other fits round the monitor stand. Mine is a steel tube 32 mm in diameter. If you want to make changes, the Fusion360 files are included. The two parts slide together (after a bit of sanding), so that you can always take your PC off without having to disassemble the monitor stand.

Printed in PETG, 15% fill, but 4 outer walls.