Size Guide
| Internal Diameter (mm) |
US | General | UK | France | Italy |
| 14.9 | 4 | / | H1/2 | 47 | 6.75 |
| 15.7 | 5 | S | J1/2 | 49.5 | 9.25 |
| 16.5 | 6 | S | M | 52 | 12 |
| 17.3 | 7 | M | O | 54.5 | 14.5 |
| 18.1 | 8 | M | Q | 57 | 17 |
| 19.1 | 9 | L | S | 59.5 | 19.75 |
| 19.9 | 10 | L | T1/2 | 62.5 | 22.25 |
| 20.7 | 11 | XL | V1/2 | 65 | 25 |
| 21.4 | 12 | XL | X1/2 | 66.5 | 27.5 |