Mechanical cipher machine M-209-B, used by the US Army

This mechanical cipher machine was designed by the Swedish cryptographer Boris Hagelin. During the Second World War, it was the standard-issue cipher machine for the US military, who called it the M-209. A total of 140,000 of these machines were in use at this time. During the war, Hagelin also supplied the French, Italians, and Japanese with different versions of his C-machine.