This submachine gun had been developed by Swedish state-owned Carl Gustaf Arms company in 1945. It is long out of production but still in service with Swedish Army, and was manufactured under license in Indonesia and Egypt (under the name of "Port Said"). Carl Gustaf M/45 submachine gun is a simple and well-designed weapon, made in a typical Swedish manner - that is, very durable and reliable.

Carl Gustaf Kpist M/45 submachine gun (Kpist stands for Kulsprutepistol - submachine gun in Swedish) is a relatively simple, blowback operated, full automatic only firearm that fires from open bolt. The receiver is made from steel tube, the separate barrel jacket is also made from perforated steel tube. Original M/45 submachine guns had removable magazine housings of two types - one for Finnish Suomi-type 50-round four-column magazines, and another - for proprietary 36-round two columns magazines. Later, the Suomi magazines were dropped from service, and the M/45B variant appeared with fixed magazine housings. The manual safety is made in the form of a hook-shaped cut made at the rear of the cocking handle slot; it is used to engage cocking handle when bolt is in retracted position. The sights consist of front blade and flip-type rear sight, marked for 100 and 200 meters. Shoulder stock is made from thin steel tubing and folds forward and to the right.