- Ian Bousfield C3 mouthpiece for tenor and bass trombone; Classic Series; wide shank; inner diameter: 1.060" (26.92mm); outer diameter: 1.575" (40mm); bore: .255" (6.48mm); silver plated; developed with international trombone soloist Ian Bousfield; manufactured with high level CNC technology EUR 186.00 - See more - Buy online