Remixed in collaboration with original Ring Holder designer Cédric Heckly.
https://www.thingiverse.com/thing:4832803
Holds 3 pre-marked (or any) marking rings for WCU-4 (maybe Preston). With glue-on bracket, you can attach the holder on a Robocup with 2 zip ties.
No supports needed for the holder. Just the bracket needs bit of supporting.
For best results print in PETG from a presliced 3MF file(Prusaslicer).
Enjoy!
The author hasn't provided the model origin yet.