Each is 1.25". The first button is the first we've seen and its design does not match the other eight. It may have been offered prior to this set. This one does have light tanning mostly on the perimeter. Of the other eight buttons the last has no back paper and the second in row two appears to have an incorrect back paper as it duplicates the paper in the first button in this row. Each of the papers name the plane pictured and offers an "Airplane Picture Book" in return from labels off the bread loaf. The Autogiro in row one has some age on the back paper but the cello remains clean. The first button in row two has some light general surface wear but all the others display Mint. Scarce group.