VINCENT BACH Trumpet Mouthpiece 11-1/2C This is a mouthpiece from BACH, a standard trumpet manufacturer. The size is 11-1/2C. "11 1/2C" Inner Rim Diameter: 15.65mm Rim Thickness: MW (Medium Wide) Cup Depth: M (Medium) It produces a bright and lively sound, with good response across the entire range. It seems to be an all-around mouthpiece that can be used with any instrument. This size is rarely available used, so how about it?