Yamaha French Horn Mouthpiece Signature Model Hiroshi Yamagishi Model Y Stage Purchased new, only test-played, so it's in excellent condition. ------ This mouthpiece has a slightly deep and large U-cup shape and a medium throat diameter, making it compatible with a wide range of instruments. The rim is thin and flexible. The cup is relatively thick, allowing for efficient sound production. Rim Inner Diameter: 17.92mm Throat Diameter: 4.11mm