Blake Corum Autographed Michigan Wolverines Full Size Speed Authentic Helmet 2 Inscriptions. This is a Blake Corum of the Michigan Wolverines hand autographed Riddell Football Speed full size Speed Authentic helmet. This item has a Beckett Witnessed Authentication, which comes with a numbered sticker hologram and a QR code for verification. You can view this item on the Beckett Authentication website, it shows when and where the item was signed. It was signed either at a public autograph appearance or a private signing. This is a stock photo of the item. Although you may not receive this exact item, the item you receive is virtually identical, brand new, and in great shape.