A little Adapter that can simply be pushed on the standard spoolholder on the Original Prusa i3 MK3S+ 3D printer. 
With the Adaptor you can now hold 2kg spools and still can fit a small/1kg spool on the holder without removing the adaptor. 
Tanks to a snug fit you can easily push the part on the existing holder but it has enough resistance to stay in its place. 

Print settings:

• 0,15/0,20 mm layer height
• supports: everywhere
• infill 20%
• rectangular/gyroid infill
• printed with the opening on the top (see cover photo)