The SIG MKMO is a submachine gun produced by Schweizerische Industrie Gesellschaft (SIG) company in Neuhausen from 1933 to 1937. The MKMO – M = Maschinen, K = Karabiner M = Militär, O = Oben – was designed for the military and to increase firepower it had a larger-capacity magazine as well as a longer barrel. Only 1,228 of these guns were produced. It saw limited adoption by Swiss police departments and the Swiss Guard at the Vatican. Finland purchased 282 of the MKMS variant, which were used by the home guard, supply units and coastal defense forces in the Continuation War.