Inner diameter: 18mm (sixze 56, the inner circumference)
Note that the bead is of the same material as the ring itself. If you want to provide your own bead (2.7 mm) you can always ask for a model without the bead, and put it in yourself.
Feel free to specify different sizes, stating the inner diameter in mm.
2.19 w x
1.534 d x
0.862 w x
0.604 d x