This is a French horn mouthpiece from Rim Inner Gold. Outer rim diameter: 25.0mm Inner rim diameter: 17.53mm Throat: 4.2 Cup: U cup Shank: SV (Suitable for Stomvi, old Yamaha (not double taper), and NEW K&M) Purchased 3 years ago. The list price was 33,000 yen, but I had it made with a Rim Inner Gold specification for an additional 14,000 yen. We are looking for buyers who understand that this is a used item.