Ultimate Brass large shank tenor trombone mouthpiece, a signature model by Koichiro Yamamoto. Yama-Tenor 5 ・Rim Inner Diameter: 26.7mm ・Throat Diameter: 7.19mm ・Cup Depth: Medium Deep I am selling this because it didn't suit me after using it for six months. There are some scratches on the body, but there are no dents and it can be used without any problems. Thank you for your consideration.