"BROR Filament Spool Holder" is an additional part that allows you to fix the "UNIVERSAL FILAMENT SPOOL HOLDER" on the BROR bookcase by IKEA. (Without that text shown at the top)
All you need is:
2X Original black M5 bolts with nuts (Given in my case, in addition, included with the bookcase).
1X UNIVERSAL FILAMENT SPOOL HOLDER by PurchenZuPoden design.
The author remixed this model.