Nate MacKinnon Signed Colorado Avalanche Reverse Retro Hockey Puck JSA 43455 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 Colorado Avalanche Reverse Retro Hockey Puck that was personally autographed by Nathan MacKinnon. Includes a certificate of authenticity from James Spence Authentication (JSA) and Denver Autographs.