This is a Bach trombone mouthpiece with the now-rare "corp." engraving. It's for a large bore trombone, size 5GS, and gold-plated. Current 5GS mouthpieces have a thinner throat, but those from this era have a thicker throat, offering a different playing feel. It's currently difficult to obtain and a popular 5GS size. How about taking this opportunity? It shows signs of use, but there is no damage that would hinder performance. It does not come with a box, so it will be wrapped in cushioning material for shipping. Thank you.