Most of the rings are based on the port code. In the port code ring size comparison table, the port code ring number ranges from 7-25, the diameter size ranges from 14.5mm to 21.0mm, and the circumference size ranges from 46mm to 66mm. The inner ring diameter corresponding to the 12th ring is 17.0mm and the circumference is 53.5mm, which is the ring number of women.
