This is an original Meyer Bros. New York Alto sax mouthpiece. This is one of the earlier vintage pieces made by Meyer. The later models said Small, Medium, and Large. Whereas the first ones said small chamber, medium chamber, and large chamber. The piece is stamped a 4 and measures out at .070". It plays great with that vintage Meyer sound that everyone strives for. It's the closest sound to Canonball that we've ever been able to get. A lot edge, and brightness. What a great alto mouthpiece.