The Yamaha 15E4 trumpet mouthpiece size is characterized by the best workmanship thanks to state-of-the-art, computer-controlled machines. The mouthpiece is particularly suitable for rotary valve trumpets. The medium wide rim ensures good endurance for the player. The deep cup provides a large and warm tone. For the orchestral trumpet player, this mouthpiece offers a great variety of sounds. The trumpet mouthpiece from Yamaha has an inner diameter of 16.92 mm and a bore of 3.88mm.