Bb/F Tenor trombone 88H Symphony. C.G. Conn Instruments standing for high quality american made brass instruments. The history shows the long periode of making experiences and getting better. But the main effort based on passion and love for music. Play and you will hear it. Features Patented CL2000 rotor system, 547" bore = 13,89 mm, Gold brass outer slides, CONN 5G mouthpiece, Deluxe wood shell case, Lacquered finish, Bell Ø 8 1/2" = 216 mm, Sterling silver, lacquered finish.