The 1991 Pro Set Football Trading Cards Series One Factory Sealed Packs contain a set of 12 standard-sized cards featuring players like Emmitt Smith, Barry Sanders, and Brett Favre. Manufactured by Pro Set, these vintage cards are from the National Football League (NFL) season of 1991 and come in English language. The packs are configured with cards made of card stock, and include players from teams like the Atlanta Falcons, San Francisco 49ers, Chicago Bears, and Dallas Cowboys. These base set cards would be a valuable addition to any football card collection, especially for fans of classic NFL stars and teams.