Thank you for viewing. This is a Walter Hilgers model WH-F4 mouthpiece for F tuba, made by the German mouthpiece maker Tilz. The diameter is approximately 30mm, which is relatively small. The cup is slightly deep, and the bore is about 8mm. I think it produces a bright sound typical of German tubas. It is a used item, so there are some minor scratches, but no major damage. There are no dents on the shank either.