Bach 335-24AW Tuba / Sousaphone Mouthpiece #24AW Bach mouthpieces are designed to meet every conceivable playing need and have for nearly three quarters of a century. Volume and excellent intonation, ease of response in the high and low register, rich, uniform timbre throughout the range, and resistance calculated to increase the player's endurance - these characteristics explain why the best professional artists choose Bach. Probably the most widely used model in the world. It's brilliant tone is preferred by school musicians.