The Courtois ACEV3B Evolution III Professional Trumpet features a .459-inch bore with a 5.03-inch bell over bell design, which features a dual wall bell construction for increase resonance and focus. The ACEV3B Evolution III also features a gap regulator design in the mouthpiece receiver, so the player can adjust the gap distance from the end of the mouthpiece to the beginning of the venturi for better note slotting. |