The M5 half track was the based on the M3 half track personnel carrier. The M5 was distinguishable from the M3 by the plating on the hull and the rounded rear corners of the hull. Like the M3, the M5 was fitted with a pedestal mount for a 0.30 cal machine gun fitted to the floor than could be dismounted. The M5A1 was a modified M5 with a ring mount M49 and "pulpit" for 0.50 cal heavy machine gun also used for AA defence.