The product is an autographed rookie trading card of baseball player Marcelo Mayer from the Boston Red Sox. Manufactured by Upper Deck, this card is a valuable collectible for fans of Major League Baseball. As a rookie card, it holds special significance for collectors looking to add a piece of the player's early career to their collection. This autographed card offers a unique and one-of-a-kind item for fans of Marcelo Mayer and the Boston Red Sox.