Trumpet mouthpiece - produced using the most advanced computer design and manufacturing technology. Standard Series mouthpieces feature unmatched precision, smooth attack, secure control, and easy playability. They have the ideal weight for all-around usage and are available in over 100 configurations. Deeper cup than the 17B4. Powerful, dark sound. A popular choice with symphony orchestra players. It has 17.3 mm rim inner diameter and 3.65 mm throat.