Bb/F Tenor trombone 52H Artist. 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 F-attachment, Dual bore .525"/.547" = 13,34/13,89 mm, Bell Ø 8 5/8" = 219 mm, Gold brass bell, CONN 6 1/2AL mouthpiece, Wood shell case, Lacquered finish.