Amari Cooper Signed Dallas Cowboys Helmet with Beckett COA. Amari Cooper autograph signed in black ink and jersey number "19" inscription, on a grey Dallas Cowboys Helmet complete with Beckett COA. Amari Cooper is a wide receiver for the Dallas Cowboys after being traded from the Oakland Raiders in 2018. The Biletnikoff Award winner was selected with the fourth overall pick by the Oakland Raiders out of Alabama in the 2015 draft.