This is a mouthpiece favored by high-note hitters such as Walt Johnson, author of "Double High C in 10 Minutes," and Roger Ingram. Production has now been completed. This mouthpiece was developed based on a mouthpiece design created in Europe in the 1920s. The inner diameter is between a Bach 10-1/2 and 12. The rim is flat and quite thick. The mouthpiece feels soft on the mouth, making it less likely to hurt or tire even with hard pressing. The outer edge of the rim is distinct, making it easy to grip. The cup is a bowl-shaped, extremely shallow cup, shallower than a Bach F. The throat is slightly narrower than a #28 (3.57mm). The straight section of the throat is quite long. The backbore is similar to a Warburton 7. It has a good response and is very brilliant, especially designed for easy high-note control. Recommended for players who control high notes without pressing. Please feel free to ask if you have any questions.