Bach is our most requested brass mouthpiece because of their long history of high quality and consistency.******Medium deep cup with medium wide, well rounded rim. The same rim and cup as No. 6 1/2 A, but with a larger "G" throat and #420 backbore for trombonists who strive for a Teutonic tone quality. Recommended for euphonium players who desire a round, mellow tone of great carrying power and substantial volume.******Other models available. Please call for more information.