This is a fantastic vintage Meyer Bros. mouthpiece for the alto sax. This piece dates back to the early New York days and is still in outstanding original condition. It is stamped a 4M medium chamber, but measures closer to a current 6M at .075". The piece shows only minimal wear despite its age, a couple light scratches is it. The original tip and rails are perfect, there are no grooves in the bite plate, and no cracks or nicks anywhere.