The 1966 Philadelphia Gum football card set contains 198 standard-size cards featuring NFL players. The cards were issued in five-card nickel packs which came 24 packs to a box and cello packs. The card fronts feature the player's name, team name and position in a color bar above the photo. The NFL logo is at upper left. The card backs are printed in green and black on a white card stock. The backs contain the player's name, a card number, a short biography, and a "Guess Who" quiz. The quiz answer is found on another card. The last two cards in the set are checklist cards. Each team's "play card" shows a color photo of actual game action, described on the back. The cards are numbered within team with the players arranged alphabetically by last name. The set features the debut of Hall of Fame Chicago Bears' greats Dick Butkus and Gale Sayers. Other Rookie Cards include Cowboys Bob Hayes and Chuck Howley. Comic Transfers sheets were included as inserts into packs.