This is one of the first Tone Edge mouthpieces produced by the Otto Link company. It was manufactured in New York before the company moved to Florida. It is table stamped a 7 and measures out at .100" exactly. The piece is completely original and is in fantastic condition for being over 50 years old. These mouthpieces are incredibly sought after, and this is a great example both physically and sonically of what a good vintage hard rubber Link should be.