Bach Cornet Mouthpiece 3C Cup Depth - M (Medium) Diameter - 16.30mm Rim - MW (Medium Wide) A larger cup, suitable for all-around use. Thank you for viewing. I am selling this because I am using other mouthpieces. (Some blurring has been applied to the photos.) As there is no outer box, I will repackage it before shipping. I have used it for about 4-5 years, so there is some wear and tear, but I think it is in good condition.