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. Fairly large rim diameter with a shallower cup than the 15C4. Outstanding flexibility. Suits Bb, C, D, and Eb trumpets. It has 16.96 mm rim inner diameter and 3.65 mm throat.