This is an excellent example of an early 1940's vintage Otto Link "Tone Master" Tenor mouthpiece. It is all original, with a serial number of F82, and an original 4 tip opening. This piece is incredibly reminiscent of Coleman Hawkins. It has that deep, full resonance that Hawkins was known for. If you can find a good one of these old "Tone Master" mouthpieces you should definitely check it out.