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  IAR80

The IAR80 was a fighter manufactured by Industria Aeronautica Romana in Romania.  Primarily used by the Royal Romanian Airforce.  Introduced in 1941.  Approximately 350 built.

  Ikarus IK-2

The IK-2 was a fighter manufactured by Ikarus A.D. in Yugoslavia.  Primarily used by the Royal Yugoslav Airforce and the Airforce for the Independent State of Croatia.  Introduced in 1935.  Approximately 12 built.

  Ikarus IO

The IO was a coastal reconaissance flying boat manufactured by Ikarus in Yugoslavia.  Primarily used by the Yugoslav Royal Navy.  Introduced in 1926.  Approximately 40 built.

  Ikarus SM

The SM was a biplane flying boat manufactured by Ikarus in Yugoslavia.  Primarily used by the Yugoslav Royal Navy.  Introduced in 1925.  Approximately 40 built.

  Ilyushin Il-4

The Il-4 was a bomber/torpedo bomber manufactured by Ilyushin in the Soviet Union.  Primarily used by the Soviet Air Force.  Introduced in 1936.  Approximately 5,250 built.

  Ithaca Model 37 Featherlight

The Model 37 is a pump-action combat shotgun that is still used today.  Manufactured by Ithaca Gun Company in the United States, the Featherlight was introduced in 1937.  It was used by U.S. military personal during close range fighting such as in trenches.  It fired a 12 gauge shell and had the capability to hold 4 rounds at once. It weighed around 3kg (7 ¼ lbs.).