To help you with the conversion of European sizes here is a comparison matrix.
Let us know if you have any questions!
Mouthpiece Widths
| Millimeters | US Size Inches |
| 110 | 4 ¼ |
| 115 | 4 ½ |
| 120 | 4 ¾ |
| 125 | 5 |
| 130 | 5 |
| 135 | 5 ¼ |
| 140 | 5 ½ |
| 145 | 5 ¾ |
Mouthpiece Diameters
| Millimeters | Inches |
| 14 | 1/2″ |
| 16 | 5/8″ |
| 18 | 3/4″ |
| 21 | 7/8″ |
| 23 | 1″ |