Yamaha French horn mouthpiece, 34C, gold-plated finish. Used very few times. * There are minor scratches from inserting into the instrument, but they do not affect performance. From the Yamaha website: Model Number: HR-34C Inner Diameter: 17.81 Bore: 4.09 A U-cup model that provides powerful volume, rich resonance, and excellent projection. The slightly thinner rim enhances flexibility and high-range playability. Included mouthpiece for YHR-869(G)D.