Karl Mecklenburg Autographed/Signed Denver Broncos 8x10 Photo BAS 31928 HM The number in the listing title is just an inventory sku for our records and is not the authentication number. This is an officially licensed 8x10 photo that was personally autographed by Karl Mecklenburg. Includes a certificate of authenticity from Beckett Authentication Services (BAS) and Denver Autographs.