The Light Tank M2 was an American pre-World War II light tank which saw limited use during World War II. The most common model, the M2A4, was equipped with one 37 mm (1.5 in) M5 gun, one .50 M2 Browning machine gun, and five .30 cal M1919 Browning machine guns.It was originally developed from the prototype T2 tank built by Rock Island Arsenal, which had a Vickers-type leaf spring suspension. The suspension was replaced by the superior vertical volute system in the T2E1 series of 1935.