Filament spool holder to easily hang on ELFA rails next to your printer, also fits on their wall board with same holes. Convenient way to hang filament spools if you have your printer on such a shelf system.

Uses a piece of 4mm PTFE tube to reduce friction. Ideally printed on its side, will need supports for the hooks at the back to work.
Have printed one each in PLA and ASA, both work fine and have no problem holding the weight of a 1kg spool.