Bruno Tilz trombone mouthpiece, a signature model of Prof. Doms, who was a soloist with the Berlin Philharmonic. - Model: Bruno Tilz - Type: Trombone Mouthpiece - Model Name: Prof. Doms - Size: Cup is 1, shank is 2. I believe this was the largest size in the Doms model. I measured the size with calipers, but please consider this as a reference only. The gold plating is applied afterward and is still quite beautiful. The shank was originally a large shank, but it has been modified to a medium-thin shank to fit a Cerveny Kaiser Baritone. Please be aware of this before considering a purchase. Thank you for looking.