This Autographed Baseball with the inscription of "HOF 84, Keep Swinging" has been Personally Signed by Harmon Killebrew of the Minnesota Twins. This item is 100% Authentic to include a hologram by Beckett Authentication Services. This item will come with an affixed Beckett Authentication Services (BAS) authentication sticker, which includes a scannable QR code to verify authenticity. Please note that Beckett no longer provides serial-numbered COA cards, and the attached BAS sticker will serve as the complete authentication for this item. The authenticity can be verified on Beckett Authentication Services website.