This is a Yamaha French horn mouthpiece, model 33C4. I purchased it new about six months ago and used it several times. Yamaha mouthpieces have very little variation between individual pieces. I am selling it because I switched to a similar model. It has been used, so there are some minor scratches, but there are no scratches that would affect playing, nor any visible distortion of the shank. Model: 33C4 Inner Diameter: 17.68mm Bore: 3.98mm Description: A model with a larger rim diameter than the 32C4. The U-cup allows for playing with a rich, well-defined sound (from Yamaha's sales page).