Rui’s rendition: Three German soldiers in body armor

Three German soldiers in body armor demonstrate the use of a 2 cm Becker-Flugzeugkanone Type M2 mounted on an anti-aircraft platform. Late war period
The Becker Type M2 began mass production in November of 1916 being used both by the military aviation and the army. It equipped among other types, twin-engine bombers such as the Friedrichshafen G.IIIa, AEG G.IV, and Gotha GIV. Initially employed by the army in an anti-aircraft role, it was later installed on a heavy-MG tripod, and used as an anti-tank gun. I also found mention of two examples being used by the Austro-Hungarian Army as anti-aircraft guns. There’s photo evidence of at least one.
The guns used in an anti-tank role (renamed 2cm Tankabwehrkanone Becker M II) were not popular among the troops. The 2 cm caliber was deemed too small as was the penetration power of its 140 g shell. Despite this, about 200 guns still managed to reach the front.
Early models of the later world-famous Swiss 20mm Oerlikon gun were based on the 2cm Becker cannon whose patent had been sold by Stahlwerke Becker AG to Swiss SEMAG in 1921 which in turn later became part of Oerlikon.
Some extra technical data:
Length 1370 mm, weight 30 kg, rate of fire 325 shots/min (due to the magazine’s small capacity (10 or 15 shells) the actual rate of fire was much lower, below 100 shots per minute.
Also of interest is the stahlhelm of the soldier manning the gun. It seems to be painted in one single light color.
Original’s source unknown