French Horn Mouthpiece Yamaha HR-IDE Special Production Model This mouthpiece features a standard-depth U-cup, a medium-sized throat, and a thin, flexible rim. The cup is relatively thick, allowing for efficient sound production. It's particularly well-suited for controlling the high register and is ideal for instruments with a narrow bell. Inner Rim Diameter: 17.43mm Throat Diameter: 4.09mm Purchased and used a few times, then stored. No scratches or dents. Price not negotiable.