Riddell Buffalo Bills Speed Authentic helmet, signed on the right side in black marker by Bills star WR Stefon Diggs.

The helmet was signed at an official paid private autograph session.

Affixed to the helmet are numbered tamper-proof authenticity holograms from The Autograph Source and Beckett Authentication Services.

Sold with  Certificates of Authenticity from The Autograph Source (Lifetime Guarantee) and independent third-party authenticator Beckett Authentication Services (BAS).