Greg Black trumpet mouthpiece, a two-piece set with a 1-1/4C cup and a 6S backbore. I purchased this several years ago when Mr. Greg Black visited Japan. I used it for about a week. The 6S backbore is said to be similar to a Bach 10. I am not considering selling the cup and backbore separately at this time, so please purchase them as a set. If you are interested, please consider it.