The Bach 50BO single rotor bass trombone features a 9-1/2" one-piece hand-hammered yellow brass bell that has defined the symphonic sound for generations. The .562" large bore combined with the open wrap F attachment offers outstanding clarity and projection with less resistance. The chrome-plated nickel silver inner handslide tubes provide the ideal surface for smooth and quick handslide action. The clear lacquer finish adds a subtle warmth to the sound overall. The Bach 50BO professional bass trombone is ideal for both symphonic and solo performance.