The M21 Mortar Motor Carriage is the 81mm mortar mounted on the standard M3 US Army halftrack. The mortar was mounted to fire over the rear of the vehicle and was widely used by the US Army in World War Two in Europe. Over 100 of these mortars were made but they were considered obsolete by the end of World War Two, the Army wanted larger caliber mortars and fully tracked mortar carriers. This is an excellent and highly detailed model by Roco.
US M21 Halftrack