Complete set of 13 lithos issued c. 1957. All are 7/8" with the exception of larger button titled "Sky Observer/Space Satellite/Official." This is 1-3/8". Exact text on the buttons is listed in Hake's Buttons In Sets. Artwork includes flying saucers, a martian, a moon man, four depict or say the word "Sputnik" and two depict or say the word "Mutnik." One shows the dog within a flying spaceship, the other shows him full figure wearing a globe-like space helmet. Large button has 1/16" white rub mark but o/w the entire set is essentially Mint. This was Hake's file set for many years and we've never been able to offer another full set. Comes with Hake's COA.