A San Francisco 49ers Speed Flex Authentic NFL Helmet hand signed by Nick Bosa. The item and signature are in excellent condition. Nick Bosa is an American football defensive end for the San Francisco 49ers of the National Football League; that also played college football at Ohio State. AUTHENTICATION: The item has been tagged with a SmarTag powered by Prova Technology; which gives you digital access to the item's authentication records; including a proof picture from the signing.