The 2025 Topps Series 1 Training Grounds U Pick Your Player Complete Your Set trading cards are a mix of players from the Major League Baseball (MLB) league. Manufactured in 2024 by Topps, these standard-sized cards are made of card stock and feature a modern design. The original insert cards are part of the 2025 Topps Series 1 set and are in English language. Perfect for collectors looking to complete their Training Grounds set with various players and teams represented.