This is a 10x13 Photo that has been Personally Signed & Autographed by Charles H. Mayo. Mayo co-founded the Mayo Clinic with his brother, William. Mayo added "with best Regards to Dr. George G. Kimmell". This item is 100% Authentic to include a Certificate of Authenticity (COA) / hologram by PSA/DNA #Y01659.Press Pass Collectibles offers a 100% Lifetime Guarantee on all Autographed & Signed Charles H. Mayo memorabilia.