The American M15 halftrack was an army SP Anti Aircraft gun on a half track chassis. Equipped with an automatic 37mm automatic cannon and two .50cal HMGs on a co-ax mount in a fully rotating turret. These were used in platoons with the M16 Anti-aircraft vehicle, 2 of each in the platoon.
Introduced in 1942 it was used extensively both in the European as well as Pacific Theatre, often in an infantry support role and was considered to be an excellent weapon system. Over 2500 were produced.