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. Even deeper cup than the 17C4 for an exceptionally dark, heavy tone. Good for symphony orchestra players who prefer a mellow sound. It has 17.3 mm rim inner diameter and 3.65 mm throat.