Data Disc For Type MB-8 Flight Computer F-100A One Set (2 Separate Discs Only) P/N FAA91-12 contains two separated discs disc number 2-1A and disc number 4-1A great for collectors in original sleeve as issued by the USAF in April of 1958 made by G Felsenthal & Sons has been stored in climate controlled warehouse very nice item for enthusiasts, buy more save more please contact with any questions (LAST ONES)