This gun had originally been designed to serve as on-board defence of Zeppelins against enemy fighters, but as the advent of incendiary bullets had put an end to the military use of these big airships, these guns were made available for the use of the Army, as light Anti-Aircraft Artillery. It hade a very short barrel (L/14.5) due to the fact it was designed to be as light and agile as possible (it weighed only 215kg deployed), but the gun was still capable of firing a solid tracer-shot (0.450kg heavy) with a muzzle velocity of 350 meter/sec up to a height of 2.2km. Also, the rate of fire was a pretty impressive (but theoretical) 120 rounds a minute. The problem, however, was here the 10-round-clip, that took six seconds to change, often causing the gunner, sitting on his seat, to lose his aim. The gun used in principle the same mechanism as the famous Luger P8 pistol, employing the recoil force for charging the gun from the clip on top – note that the clip is missing on the photos below – and also for throwing out the spent cartridge etc. For moving the gun a small cart was used, pulled by two horses. (In an emergency, it could be man-handled or pulled just by one horse.) For transport it was broken down into four loads. It was not too successful, being originally designed for another use: not only was the practical rate-of-fire too low, but the mechanism was sensitive and easily jammed by sand and other particles. But the hard-pressed Germans simply had to make do, and the first guns reached the troops in December 1917. In November 1918 some 150 of these Sockelflak guns were in service.