2026 Topps MLB Series 1 Baseball Trading Card Celebration Box

2026 Topps Series 1 Baseball Celebration Mega Box is a special-edition release timed for MLB® Opening Day (March 26) that celebrates both the annual Series 1 launch and the 75th anniversary of Topps Baseball. Collectors can build the 350-card Series 1 base set (veterans, rookies, stars, legends, Future Stars, League Leaders, and team cards) while chasing exclusive parallels and insert content such as Walk This Way, Gameday Drip, Mascots, and more.