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. The 14B4 rim with a unique cup for a soft tone. For rotary trumpets. Large backbore and throat. It has 16.84 mm rim inner diameter and 3.88 mm throat.