Redbacks are filecards that are red on the back of the cards, making them distinctly different than the standard filecards. The Redbacks were issued bagged with figures through Hasbro Direct via mail-order promotions and also on bubbles through J.C. Penney's and Sears exclusives in 1982 and possibly 1983 and 1984. If you have additional information about the J.C. Penney's or Sears sets please contact me at dmooretoys@yojoe.com.