Dak Prescott Autographed/Signed Dallas Cowboys 16x20 Photo Beckett 34888 The number in the listing title is just an inventory sku for our records and is not the authentication number. The item pictured is a stock photo unless otherwise noted. This is a 16x20 photo that was personally autographed by Dak Prescott. Includes a certificate of authenticity from Beckett Authentication Services (BAS) and Denver Autographs.