Thank you for viewing! This is a French horn mouthpiece, the JK EX model 2DM. I used it about 4-5 times, and otherwise, it was stored in a mouthpiece case. Cup inner diameter: 17.5mm Bore size: 4.2mm Cup shape: U cup It's neither too wide nor too narrow, and has a moderate resistance, making it easy to play. It will be shipped in a plastic case, packed with bubble wrap, etc.