This is a cover to protect the electronics from the up4000 boards, its held by two of the screws that held the heat sink. Just unscrew them, place the cover and screw them back again.
I printed it horizontal with support on the base for a better surface quality.
Edit: I added a new model to mount the computer upside down with M3 screws.
Category: Computer
The author marked this model as their own original creation. Imported from Thingiverse.