Great reproductions of curious post stamps with the Führer, but made by American war-time Office of Strategic Services (OSS) - precursor of CIA. 
It was made as a part of a program to spread dissent in the Third Reich by sending falsified letters and anti-Nazi propaganda to real people across Germany. The caption says "Futsches Reich" meaning "Lost Empire". 
OSS falsified post-stamps, postal rubber-stamps, mail sacks to be indistinguishable from authentic ones. Then they would drop the sacks full of fake letters from low flying airplanes around bombed trains and train stations. Germans would diligently pick up the sacks and deliver them to the intended recipients completing the mission. Read more on "Operation Cornflakes" if you are interested. 
Sold in strips of 5.