The 2021 MLB Topps Opening Day Baseball Hanger Box is a factory sealed pack containing 35 standard size trading cards featuring players from the Major League Baseball (MLB). Manufactured by Topps, the box includes a variety of cards such as serial numbered, hologram, short print, stamped, and base set cards. This product also includes parallels, 1st edition cards, inserts, and cards for chase collectors. The pack is in English and is officially licensed by the MLB, making it a sought-after item for baseball fans and collectors.