This NBA Basketball was hand signed by Milwaukee Bucks star Giannis Antetokounmpo at a private signing. It is accompanied by a Certificate of Authenticity from SportsMemorabilia.com and Beckett. A tamper-evident hologram will be affixed to the item. Signed items are guaranteed to pass any third-party authentication with 100% Money Back Guarantee. Each signature is witnessed by a member of our staff or comes out of a private signing.