| Model No. | Inner Rim Diameter (mm) | Rim Contour/ Thickness |
Cup Depth | Throat (mm) | Backbore | Playing Characteristics |
|---|---|---|---|---|---|---|
| 37C4 | 18.60 | semi-flat/ standard |
standard | 5.25 | standard | Medium inner rim diameter and cup volume. Bright tone. Easy to play from the lowest to highest notes. Outstanding endurance. |
| 38D4 | 18.90 | semi-flat/ standard |
Semi-deep | 5.25 | standard | Large inner rim diameter and a fairly deep cup produce a rich, heavy tone. Popular with top British amateurs. |
Yamaha Alto Horn