The PK is a 7.62 mm general purpose machine gun designed in the Soviet Union and currently in production in Russia. Its NATO equivalents are the FN MAG, MG3, and M60 machine guns. The PK machine gun was introduced in the 1960s and replaced the SGM and RPD machine guns in Soviet service. The PK machine gun can be used as a light anti-aircraft weapon when it is put on an AA mount. One feature typical to Soviet machine guns is that the standard model feeds from the right and ejects its spent cases via an ejection port on the left side of the weapon, as opposed to the right side ejection port seen in most western machine guns.