New York Yankees rising stars Gary Sanchez and Didi Gregorisu have both hand signed this baseball. Didi added the inscription "NYY SS HR Record 2017" and Sanchez added the inscription "NYY C HR Record 2017". This baseball is limited to only 17 and the This baseball comes complete with the Steiner Sports certificate of authenticity and tamper proof hologram. This ball also comes with MLB authentication. Authenticator : Steiner Sports Authenticated History of item : Sanchez and Gregorius have signed this item in the presence of a representative from Steiner Sports.