This is a model for Ikea Skadis to mount a Ubiquiti PoE injector.
You need 2x M4 Nut and 2x M4x8 Screw.
The original model is from ari.mandjelikian Customisable Stabilised Ikea Skadis Hook multiple sizes
https://www.printables.com/de/model/100876-customisable-stabilised-ikea-skadis-hook-multiple-
The author remixed this model.