This is a mounting bracket for the Mean Well RS-75 power supply. It was designed around some 2020 v-slot extrusion, utilizing M3 hardware to mount. I'm sure it could easily be adapted to larger extrusion and fasteners.
The mounting boss attaches to the holes on the back of the power supply with two M3 screws. I recommend an M3x6mm screw to avoid coming in contact with the back of the power supply PCB.
The bracket attaches to the extrusion using the appropriate extrusion nuts and screws.
The author marked this model as their own original creation.