This is a McWilliam Model 3 mouthpiece. It has a European shank. I have stored it since I purchased it and have never used it. Inner rim diameter: 17.5mm Cup: Shallow Throat: 4.0mm Retail price: 16,500 yen The shallow cup makes it easier to play in the high register. Purchase date: End of February 2024. I can send more photos if needed. Thank you.