Riddell Speed Authentic Michigan Wolverines football helmet, signed on the right side in silver marker by Aidan Hutchinson.  This is the nice version of the helmet with painted wings (not decals).

Signed at an official paid private autograph session.
Sold with a Certificate of Authenticity from The Autograph Source.

Authenticated by independent third party authenticator Beckett Authentication (BAS QR Code Hologram affixed to helmet — the authenticity COA is referenced in their online database).