The picture shows the (2) CerealBox Backs With Cartoon Character Playing Cards in this lot. These are believed to be from the back of 1960s Kelloggs Corn Flakes Cerealboxes. Both panels have the same cards which include the following Hanna Barbera cartoon characters:
To judge the sizes they each measure about 7-1/4" x 7-1/4". They are in good to very good condition with being unevenly cut and the discoloration as pictured.