Adidas Golf Signed Cap Hat from 2017 Royal Birkdale Open Golf Championship.

I believe it has the following signatures:

Patrick Reed, Billy Horschel, Adam Hadwin, Roberto Castro, Brandon Stone, Jimmy Walker, Aaron Baddeley, Bill Haas, Cameron Smith, Brandon Grace, Thorbjorn Oleson, Henrik Stenson, Charl Schwartzel, Tony Finau, Hideto Tanihara, James Hahn, Hideki Matsuyama, Francesco Molinari, Danny Willett, Jhonattan Vegas, Phil Mickelson, Shane Lowry.

Please see photos.