Shai Gilgeous-Alexander Ousmane Dieng OKC Thunder signed jerseys. A must-have for any OKC enthusiast. Authenticated by James Spence Authentication (JSA), you can be assured of its authenticity. Buy with confidence Autographs received in person. Indeed, I have an extensive collection of genuine Shai autographs, assured to be authentic. Should they be deemed counterfeit, a refund of five times the purchase price will be issued. Authentication reports from JSA, BSA, or Becket must be provided in writing. Buy with assurance.