1.25" blue and silver button used to promote 1939 Universal serial starring Buster Crabbe. Text reads "Buck Rogers Strange World Adventure Club" and shows Crabbe in space helmet with rocketship to the right plus faint figure of man holding space gun at lower right. Button was issued along with a membership card by movie theater. Complete with Phila. Badge backpaper. One of only six seen in four decades. Sales have all been in $2000 - $3000 range, if undamaged, and the only exceeding trivial issue with this one is loss of some brassy tone flashing from metal rim of reverse. The celluloid front is exceptionally free of surface wear, even under magnification. Exc. and visually a superb example displaying Mint.