While Bach Alto Horn and Mellophone Mouthpieces have identical rim and cup shape, the alto horn mouthpieces have a slightly larger shank.

DEG Mellophone Mouthpiece 6V

Many trumpet players have used this mouthpiece for lyrical orchestral solos in the posthorn relm. We have also threaded a great number of these to except screw rims for those who want a larger diameter. A great mouthpiece to have in your arsenal.