Riddell Full Size Replica speed helmet hand signed by Green Bay Packers Linebacker ISAIAH McDUFFIE. The signature is in Black sharpie with the inscription "GO PACK GO". This item was signed at a private signing with us and would make a great addition to any Packers collection! This autograph is guaranteed to be 100% authentic and will include a COA hologram from Beckett Authentication. This item was signed at a public signing with us.