The Bach 50BO single rotor bass trombone features an 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.