Automatic rifle with folding stock, 9 mm (0.35") Largo caliber, and options for semi-automatic or automatic fire, with magazines holding 10 and 30 cartridges. Manufactured from 1946 onward, it was an improved design that innovated on the German MP40 model. The Civil Guard received the weapon more than 10 years later than the Army, and both the Traffic Corps (Agrupación de Tráfico) and mobile units assigned to the Territorial Guard (Guardia Territorial) in Spanish Guinea received it from 1959. In order to differentiate it from the submachine gun Model C, it was known as a “metralleta” (machine gun), even in regulations.