Furguson, an American mouthpiece maker, presents the trombone and euphonium mouthpiece "4G-5G" for large bore instruments. Inner Diameter: 26.1mm Throat Diameter: 7.13mm Cup Depth: Medium deep This is a B series mouthpiece, which is not often imported domestically. The size feels similar to a Greg Black 4G-5GM, but the rim is designed to be closer to a Denis Wick, so it feels flatter and provides a more secure hold than a Greg Black. I think it will produce a warm and full sound. There are some scratches from use, but it is relatively clean. Feel free to comment if you have any questions!