This is a din rail mount for MAX31865 breakout boards. You will need the Voron din rail clip as well, it can be found here: https://github.com/VoronDesign/Voron-2/blob/Voron2.4/STLs/Electronics_Bay/pcb_din_clip_x3.stl
Print both files and then use some M2 screws to mount the PCB to the holder. It has cutouts for the M2-Nuts.
After that, use two self-tapping M2 screws to mount the din rail clip to the holder.
The author marked this model as their own original creation.