M55

The M55 was an American quad anti-aircraft machine gun emplacement designed in 1942 by the Kimberley-Clark Corporation. Between 1943 and 1953, about 10 000 M55s were used by the United States Army. It could be towed by a utility vehicle or mounted on an APC. It used four rapid firing 12.7mm (.50 cal) machine guns that fired simultaneously at low flying low speed aircraft.

Battlefield Vietnam
In Battlefield Vietnam, the M55 is an emplacement used by the United States military. Its role is essentially an anti-aircraft turret, which is very effective against enemy helicopters and even jets.