In 1954 the "General Direction of Military Fabrications" (D.G.F.M.) built a prototype that would be the initiator of a new modernized streetcar body.
Three years later the series construction of the "F.M." began which would occupy the series from 3301 to 3577; With a weight of 10.7 tons, 9 windows and 36 seats.
Like all units put into service in the 1950s, they were painted aluminum with a blue band under the window line.
The number of cars in the stations at the end of the tram service in Buenos Aires was 277,number 3361 is the only one preserved.
