thingiverse
This is a set of 17 rings from size 0 to 16. Each has the size of the ring inscribed into the ring. Print it yourself or get it printed for as low as $19.04 here http://shpws.me/3hka
added small which is 106x102mm platform which should be printable on smaller platforms.
Instructions
1) Print or buy ( http://shpws.me/3hka )
2) try on until you find ring that fits
3) remember size of ring when ordering rings online.
Direct link to the original creator's page
Click the "View on thingiverse" button above to visit the original model page on thingiverse. You can download the STL file directly from the creator's page for free.
This STL file is compatible with most FDM 3D printers (Creality Ender 3, Prusa MK3S+, Bambu Lab, etc.) and resin printers (Elegoo, Anycubic). Check the original page for recommended print settings and materials.
Yes, this model is available as a free download on thingiverse. Some creators accept tips or donations.
Most STL files can be modified using free software like Blender, TinkerCAD, or Meshmixer. Check the license on the original thingiverse page to see if modifications are permitted by the creator.