These comic buttons were pack inside specially marked boxes of Kellogg's® Pep® cereal between 1945 and 1948. Here we have an example of that box; the front of the box has an ad for the Pep pins including an image from Superman, the back panel features a Superman 8-panel comic strip from a numbered series of at least 12. This is #1 and titled "Superman and The Terrible Underseas Monster." Back panel also mentions the Superman radio program. Kellogg's Pep cereal were the first sponsors for the radio show in 1945 and Kellogg's continues its association with the character through 1957 for the duration of the Adventures of Superman TV show.