This is a vintage Selmer Magi-Tone Alto Saxophone mouthpiece. These mouthpieces are incredibly rare!! We haven't even seen very many of them. This specific example is from an Ebay listing. There mouthpieces overall are very similar to the vintage Air-Flow mouthpiece made by Selmer. This one even has its original Magni-Tone Ligature. These ligs can change to fit both Alto sax and Clarinet.