This is a First Day Cover that has been hand signed by the great, Leo Durocher. The cachet has been authenticated and slabbed by PSA/DNA. The serial number is verifiable online using PSA/DNA #84092328. The cover comes encapsulated in a tamper-proof cover. 100% authentic signature from Brooklyn Dodgers legend, Leo Durocher. A great gift idea for a Brooklyn Dodgers or MLB collector.