9x12" mailing envelope comes w/two-piece premium issued by Ralston Wheat and Rice Chex c. 1952. Envelope features illustration of Buzz Corry w/word balloon that reads "Hey Kids Here's Your Ralston Rocket Space Patrol Terra IV" and directly below this is ink stamp reading "Balloon Kit." Envelope has tanned, jaggedly torn open along right edge w/3x3" corner piece missing but VG. The first part of the premium is a stiff paper base for holding balloon w/fully opened size of 8.5x16". Has checkered pattern w/Space Patrol text area at top center, on the bottom half are pair of inset Wheat and Rice Chex cereal boxes plus illustrated instruction panel. Has very lt. wear along original fold lines but remains totally clean and Exc. Comes w/original 2.5x5" balloon that features large image of the Terra IV ship on one side that includes text on fins "Ralston Rocket" as well as ad for the ABC radio and TV programs. While the balloon remains largely complete, it has hardened w/age and has begun to disintegrate although currently sealed in a plastic bag. While this just comes along, it is the only example we've seen. The base is only the second we've seen.