It was seen in White House Down.
Manufactured by Fabrique Nationale, the FN MAG was chosen by the U.S. military for different roles after large world-wide searches and competitions. The MAG is a belt-fed, gas-operated, air-cooled, crew-served, fixed headspace weapon. Its versatility is demonstrated by its ability to be mounted on the M122A1 tripod, a bipod, on vehicles, or on aircraft.
It was first adopted by the U.S. Army in 1977, as a coaxial tank gun, and slowly adopted for more applications in the 1980s and 1990s. The M240 and M240E1 were adopted for use on vehicles. This led to further adoption in more uses, especially for the Army and Marine infantry. While possessing many of the same basic characteristics as its predecessor, the durability of the MAG system results in superior reliability when compared to the M60. The MAG actually has a more complex gas system than the M60, but gives better reliability combined with lower maintenance requirements, though this comes at greater manufacturing cost and weight.
Compared to other machine guns, its rating of 26,000 Mean Rounds Between Failure (MRBF) is quite high for its weight—in the 1970s when it was first adopted it achieved about 7,000 MRBF. It is not as reliable as some very heavy older designs, but it is quite reliable for its mass.
The M240D has two possible configurations: aircraft and egress (ground). The aircraft configured M240D has a front and rear sight and a trigger group which accommodates the spade grip device. The ground configuration involves the installation of an Egress Package or "infantry modification kit" which is designed to provide downed aircrew personnel with increased firepower. The M240D is an upgrade of the M240E1, primarily in the addition of an optical rail on the receiver cover. The M240E1 is also fitted with spade grips for flexible use.