This is a First Day Cover that has been hand signed by the great, Bill Moose Skowron. The cachet has been authenticated and slabbed by PSA/DNA. The serial number is verifiable online using PSA/DNA #84092552. The cover comes encapsulated in a tamper-proof cover. 100% authentic signature from New York Yankees legend, Bill Moose Skowron. A great gift idea for a New York Yankees or MLB collector.