This is a First Day Cover that has been hand signed by the great, Whitey Herzog. The cachet has been authenticated and slabbed by PSA/DNA. The serial number is verifiable online using PSA/DNA #84092537. The cover comes encapsulated in a tamper-proof cover. 100% authentic signature from New York Mets legend, Whitey Herzog. A great gift idea for a New York Mets or MLB collector.