Anti-aircraft gun (3.7 cm FlaK 18)
The main feature of the German air defence was that Germany was forbidden to own and develop anti-aircraft systems after World War I. This greatly thwarted any progress in making German AA guns, causing the designers to resort to all sorts of tricks and falsifications to provide the Wehrmacht with this type of weapon.
The most popular anti-aircraft gun, the 3.7 cm FlaK 18, was considered a powerful but inconvenient weapon. These guns were widely used not only on standard gun carriages but also on railroad trains, ships, and vehicles (both armoured and unarmoured).