Rob Gronkowski Autographed/Signed Pro Style Blue XL Jersey RAD 40361 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 custom pro style Blue XL jersey with sewn on name and numbers that was personally autographed by Rob Gronkowski. Includes a certificate of authenticity from Radtke Authentication Services (RAD) and Denver Autographs.