Bb B Tuba from the Symphony series. 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 3 front-action valves, 658" bore = 16,71 mm, Bell Ø 18" = 457 mm, CONN 2 mouthpiece, Hard shell case, Lacquered finish.