A Green Bay Packers Speed Salute To Service Authentic NFL Helmet hand signed by Clay Matthews. The item and signature are in excellent condition. Clay is a former outside linebacker who played for the Green Bay Packers. He is a Super Bowl Champion, 6x Pro Bowler & a Butkus Award winner. AUTHENTICATION: Your item is tagged with a SmarTag powered by Prova Technology, which gives you digital access to your items authentication records, which includes a proof picture from the signing.