The Bach 42 Stradivarius Series Professional Tenor Trombone is a perfect instrument for the player looking for a large bore trombone. The Bach 42 Series is a straight trombone featuring a .547-inch bore and 8.5-inch one-piece hand-hammered bell for increased resonance. The horn is available with a yellow brass bell with a standard handslide. The open wrap on the 42BO allows for a freer, more open sound.