This is a fan mount for the side panel of the BeQuiet! SilentBase 800 PC case. You will need this fan mount if you are using one or two GTX 980 Ti graphic cards (or one or two with a similar form factor) and a huge CPU cooler.
It is printed in ABS in three parts. No support is needed. I have glued the two huge parts with "UHU Kunststoff hart".