French horn mouthpiece, JK's Will Sanders model, SF3 18M. Cup inner diameter: 18.0mm Throat diameter: 4.3mm Cup shape: U cup Compared to the same JK EX model, even with the same inner diameter of 18.0mm, this one feels slightly larger on the mouth. This may be due to the shape of the rim. It gives the impression of a softer tone compared to the EX model. There are some scratches on the shank and other parts due to use, but there are no dents or distortions, and there is no problem with playing. I plan to keep it for myself if it doesn't sell, so there are no plans to lower the price.