The 10.5 cm FlaK 38 and FlaK 39 was a German anti-aircraft gun used during World War II. It was designed as the heavy AA gun for the Kriegsmarine, analog of the famed 8.8 cm Fla K 18 in Army use, but intended to also serve a dual-role against small surface targets as well. The Army took the program over in 1933, but produced only small numbers as the gun was not mobile and newer versions of the 88 outperformed it anyway.