French horn / mellophone / baritone / sousaphone waterkey spring.
Fits Fr. horn models:
- Holton H104 Tuckwell
- Holton H109
- Holton H177
- Holton H178
- Holton H179
- Holton H180
- Holton H181
- Holton H277
- Holton H278
- Holton H279
- Holton H280
- Holton H281
Fits mellophone models:
Fits baritone models:
Fits sousaphone models:
- Holton BB300
- Holton BB310