VINCENT BACH CORP. 11C Trumpet Mouthpiece, Old Engraving This is a mouthpiece from BACH, a standard trumpet manufacturer. The size is 11C. With the beautiful and brilliant sound unique to C trumpets, the high register is easy to play, and the low register is also free. Diameter: 15.7mm Cup Depth: M (Medium) Rim Thickness: MW (Medium Wide). Of course, it can also be used with B♭ trumpets. I think it would be more suitable for pop music, etc. It's a popular CORP. (old engraving) model even now. There is a slight dimple on the rim. There are some other minor scratches, but it seems to be in good condition.