This is a filament hanger/holder designed to fit on the top rim of the Dremel 3D20. Holds the filament spool from other brands since they don't usually fit inside. Dremel's own branded spools do fit inside (they are smaller and less thicker), but in my case (using Hatchbox PLA 1kg spool), it's way to big. Hope it helps for those out there using the same machine but different brand filaments.
Note 1: The piece has two holes on the top meant for extra support in case you want to use some small screws but they are not necessary and totally optional, the piece holds itself pretty nicely without anything extra.
Note 2: In the photos, the printed piece looks kind of messy but that's because I use the 'Fast' setup in Simplify3D and also didn't spend much time cleaning up the borders of the supports.