This is holder for a Streamdeck MK1 that attaches to the end of a 4040 profile.
The newer Streamdeck MK2 is not tested with this design.
What you need are some countersunk M3 screws (length doesn't matter, but min 6mm and max 16mm) and 2x M5 cap screws + 2x M5 T nuts.
Print the hinge with enough perimeters (I used 5) to make it durable. The 2 bigger pieces are fine with 2 perimeters.
No supports needed if printed in the correct orientation.
You can use the different holes in the backplate to fine the height of the Streamdeck relative to the 4040 profile used.
The author hasn't provided the model origin yet.