The Maschinenkanone 108 (very much not "Mark 108") is a German 30mm aircraft cannon developed by Rheinmetall‑Borsig during World War II. Intended as a bomber-killing weapon, the MK 108 was designed to excel in its specific role as opposed to being a "jack of all trades" weapon, and as such was built as compact and lightweight as possible, together with having the highest rate of fire possible; this was aided by use of the advanced primer ignition system. This resulted in a weapon that was small and light enough to be mounted in a wide variety of German aircraft, from the relatively small-framed Bf 109 (firing through the spinner) to the Bf 110 heavy fighter, but its most well-known use is a quartet of MK 108s as the Me 262 jet fighter's standard armament. Designing such a specialized weapon naturally comes with tradeoffs, in this case the most notable being the MK 108's exceptionally poor muzzle velocity.
The MK 108 and variants can be seen in the following films, television series, video games, and anime used by the following actors: