The 2026 Topps Series 1 Baseball Flagship Collection Costco Super Box contains 2 sealed boxes featuring baseball trading cards from the Major League (MLB). The autographed cards are hard-signed and authenticated by Topps, with a focus on the MLB World Series. Made of card stock, this limited edition set includes players from teams like the New York Yankees and Los Angeles Dodgers, making it a must-have for baseball fans and collectors alike.