The German 88mm anti-tank artillery gun earned one of the biggest fames during World War II, not only because it was a powerful piece of weapon that could be used against ships, ground vehicles and airplanes, more importantly because it was exactly the same gun design being deployed to the mighty German Tiger tanks series.  In post war interviews with Allied troops, they claimed that the FLAK gun was an unfair weapon being deployed in ground battle.  In German, the 88mm anti-tank artillery gun was commonly called “The FLAK gun”, the word FLAK is abbreviation of German word “Fliegerabwehrkanone” in English, meaning “aircraft-defence gun”.  

 

There were 4 major phase variants of the FLAK gun, commonly known as the 18/36/37/41 models.  FLAK 18 gun design had a single piece casted structure gun barrel, however the German army later found that due to massive usage of the gun (It usually took many shots to hit a single aircrafts) the gun firing explosion inside the gun barrel caused cracks on the gun barrel surface, but it was difficult to conduct replacement in the battlefield, subsequently the German army had developed the FLAK 36 gun barrel with sectioned gun barrel design for easy replacement.  

 

Due to supply shortage during the war, many combinations of gun barrel and the cruciform were used together, it could be a Flak 18 gun put together with the Flak 36 cruciform or Flak 36 gun with a Flak 36 cruciform.