Model 2AK Rim outer diameter: 25.5mm Cup inner diameter: 17.5mm Throat size: 4.8 Extremely deep Cup shape: K = V cup Silver-plated finish (SP) ■J.K. french horn mouthpiece Josef Klier SP ■In English pronunciation, it is Jay Kay, and in German pronunciation, it is Yott Car. Yott Car regularly researches mouthpieces with professional musicians. And with their unique technology and manufacturing methods, they solve problems that musicians have with their mouthpieces. The series include the K series, M series, and SD series. The K series has a V cup, and the M series has a U cup. There are 5 types of models based on differences in rim/cup: model numbers 01, 1, 2, 3, and 4. In addition, there are 6 throat sizes. There are only minor scratches from use, and no history of drops.