1" with no maker's name or backpaper. Although referencing the "Moon" that word seems to reference the ultimate goal of the space program as the button was almost certainly issued following his 1962 first orbital flight in Friendship 7. The item came from the Baltimore, MD area and most likely was given to employees working on the space project at that city's Westinghouse plant. Far right edge has 1/8" stress split in the celluloid but otherwise totally clean. Only example we've seen.