I made the Treedix USB Cable Tester Case that someone else made (search for it) and needed a bottom cover to go with it. 

Used Transparent Red PTEG filament, 0.15mm layer height.

I screwed it to the other 3D case (different project) through the Tester PCB using M2.5mm x 12mm screws. 

The photo is the completed unit with this 3D print on the bottom.