The Hecker & Koch MP5 is a select-fire submachine gun designed and developed by German manufacturer Heckler & Koch. Beginning production in the late 1960s, the MP5 became well known worldwide and used by many various military and law enforcement officials.
The MP5K variant is used by the Vampires, primarily in the hands of the Death Dealers at the end of the movie. Some use the foldable PDW stock while others don't, but nevertheless, they are used to kill off Lycans loyal to Lucian and try to kill Michael Corvin with the weapons, but fail in their attempt.
The weapon that appears briefly when Selene and Michael Corvin enter a Vampire Safe House, several MP5A3s with surefire grips are visible in the armory. Selene takes one of these weapons in her equipment bag, but never uses it. When entering the safehouse, another variation of the gun is seen in the hands of Selene. This variation is that of the MP5K, which is outfitted with a side mounted tactical flashlight.
The MP5A3 is used by both Vampires and Lycans, outfitted with an assortment of different devices, such as vertical foregrips, flashlights, ACOG Scopes, even stocks utilized on Heckler & Koch's other weapon, the UMP.