Bach Stradivarius 50B2 Bass TromboneThe Bach 50B2 stacked dependent double rotor bass trombone in the key of Bb F Eb 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 traditional wrap F Eb attachments offers outstanding clarity and projection with just the right amount of resistance. The chrome plated nickel silver inner handslide tubes provide the ideal surface for smooth and quick