Rim Inner Diameter (mm): 16.86 Throat Diameter (mm): 3.98 This is a rare model that is not often available used. It has a slightly smaller rim inner diameter than the 16E, producing a soft and beautiful tone. The fine sound quality allows for stable playing from high to low notes. Please contact me if you would like to see any other areas in detail. I will add photos. Cleaned and will be shipped wrapped in bubble wrap. #Cornet #Trumpet #Mouthpiece