A M-209-B encryption machine, American, circa 1942,
Serial No. 31784, supplied by the L C Smith & Corona Typewriter Inc., complete with canvas shoulder bag, spare tape and two printed instruction books dated 1942, the case 7in (18cm) wide
The M-209 was designed by the Swedish cryptographer, Boris Hagelin, in response to a request for such a portable cipher machine. It is a mechanical cipher machine that was used by the US military primarily during World War II, although it remained in active use through the Korean War.