Size Chart
| Inside Diameter | US | UK | Germany | Spain | France | Italy |
| 14 mm | 3 | F | 44 (14.0) | 4 | 44 | 4 |
| 15 mm | 4 | H | 47 (15.0) | 6,5 | 46.5 | 7 |
| 15.6 mm | 5 | J | 49 (15.6) | 9,5 | 49.5 | 9 |
| 16.6 mm | 6 | L | 52 (16.6) | 12 | 52 | 11 |
| 17.2 mm | 7 | N | 54 (17.2) | 14,5 | 54.5 | 14 |
| 18.1 mm | 8 | P | 57 (18.1) | 17 | 57 | 16 |
| Inside Diameter | US | UK | Germany | Spain | France | Italy |
| 14 mm | 3 | F | 44 (14.0) | 4 | 44 | 4 |
| 15 mm | 4 | H | 47 (15.0) | 6,5 | 46.5 | 7 |
| 15.6 mm | 5 | J | 49 (15.6) | 9,5 | 49.5 | 9 |
| 16.6 mm | 6 | L | 52 (16.6) | 12 | 52 | 11 |
| 17.2 mm | 7 | N | 54 (17.2) | 14,5 | 54.5 | 14 |
| 18.1 mm | 8 | P | 57 (18.1) | 17 | 57 | 16 |