Mason Miller Signed Oakland Athletics Jersey “The Reaper” (Beckett) A's CloserThis autographed jersey has been personally hand signed by Mason Miller of the Oakland Athletics. When signing, Miller inscribed The Reaper along with his signature. This autograph is certified by Beckett Authentication Services (BAS) Witness Certification. That means that a Beckett representative was present when this item was signed. It comes with the numbered authentication hologram with a QR code card that verifies the authentication on the