John Elway & Tim Tebow Signed 2010 Chrome Gridiron Trading Card BAS Slab 40768 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 trading card that was personally autographed by both John Elway and Tim Tebow. This has been professional slabbed by Beckett Authentication Services (BAS) and includes a certificate of authenticity from Denver Autographs.