CONN CONSTELLATION MOUTHPIECE
This is a NOS (new-old-stock) Conn Cornet Mouthpiece. I acquired a 8-9 of these mouthpieces as a set purchase 3-4 years ago. Apparently they came from Byron Autrey some time ago. Anyhow, this is a beautiful example of a 9-BW Cornet Mouthpiece.
You can find all the details on these mouthpiece sizes etc HERE