Adrian Peterson is one of the most physically dominant running backs in NFL history, a 2012 MVP who rushed for 2,097 yards in a single season — eight yards shy of Eric Dickerson's all-time record — and spent the prime of his career terrorizing defenses in purple and gold. This Minnesota Vikings Riddell Speed Flex Authentic helmet has been personally autographed by Peterson, a fitting tribute to a man known as "All Day" for the relentless way he played the game. It's an iconic piece for any Vikings fan or collector of football royalty.