| Model | Application | Cup Diam. | Bore | Backbore | Description |
|---|---|---|---|---|---|
| 4AM | Pre-1974 B&H | 26.00 mm | 7.38 mm | barrel | Classic euphonium mouthpiece - old fitting |
| 4AY | USA & Jap. fitting | 26.00 mm | 7.38 mm | medium | As above |
| 6BM | Pre-1974 B&H | 25.40 mm | 7.12 mm | medium | Like 6BL with euphonium bore |
| 6BY | USA & Jap. fitting | 25.40 mm | 7.12 mm | medium | As above |