| ITALY / IT | DIAMETER / DIAMETER (mm) | USA |
|---|---|---|
| 10 | 15.9 mm | 5 |
| 12 | 16.5 mm | 6 |
| 14 | 17.2 mm | 7 |
| 16 | 17.8 mm | 7.5 |
| 18 | 18.4 mm | 8.5 |
| 20 | 19.1 mm | 9.5 |
| 22 | 19.7 mm | 10.5 |
How to measure: wrap a thread around your finger and measure the inner diameter in millimeters.
| ITALY / IT | DIAMETER / DIAMETER (mm) | USA |
|---|---|---|
| 10 | 15.9 mm | 5 |
| 12 | 16.5 mm | 6 |
| 14 | 17.2 mm | 7 |
| 16 | 17.8 mm | 7.5 |
| 18 | 18.4 mm | 8.5 |
| 20 | 19.1 mm | 9.5 |
| 22 | 19.7 mm | 10.5 |
How to measure: wrap a thread around your finger and measure the inner diameter in millimeters.