The Walther MP series consists of a family of 9 millimeter submachine guns which were manufactured and produced in Germany from 1963 to 1987. MP is an acronym for Maschinenpistole.
There are two versions of the submachine guns: MPK (Maschinenpistole Kurz or "short submachine gun") and MPL (Maschinenpistole Lang or "long submachine gun"). The high-quality submachine guns were used officially by German police forces and widely exported, the Portuguese Navy and the Mexican navy. The United States Navy SEALs used both versions of the Walther MPK in Vietnam.
The sole difference between MPK and MPL guns is the extended length of the barrel. The Walther MPK models are blowback designs exclusively firing from "L"-shaped bolts. The bolts are above the barrel which permits a shorter receiver. The Walther MPK receiver forms a ventilated cooling jacket and is made from stamped steel. The Walther MPK's prominent cocking handle is located on its left front. Behind the trigger, Walther has positioned a selective fire switch on the left side of the receiver.
The MPL has 100 and 200 meter settings, whereas both guns feature flip-up sights. Both guns also feature side folding buttstocks made exclusively from thin steel tubes.