SIZES
The mesure is in mm for example 18,20 mm is 1,82cm.You have to mesure the diameter of one your rings, and there you go, you´ll have your size!
Nº- 10 = 15.70
Nº- 12 = 16.30
Nº- 14 = 16.90
Nº- 16 = 17.50
Nº- 18 = 18.20