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