Dalvin Cook, star running back for the Minnesota Vikings, has hand signed this Vikings Riddell Speed full-size replica helmet at a private signing. This item comes with a certificate of authenticity (COA) from JSA - James Spence Authentication and was signed in the presence of one of their representatives. You will receive a serial-numbered COA along with a matching serial-numbered sticker on the helmet. The authenticity can be verified online by entering the serial number.Item pictured may not be the exact item you will receive. It will be similar quality, and we guarantee your satisfaction.