Sd.Kfz 251/10 ausf D (3.7mm Pak) Half TrackPanzergrenadier units in armoured half tracks, trucks and field cars helped the infantry to keep pace with their armoured brethren. By the time of the invasion of Russia in 1941 the panzergrenadiers had equipped their troop leaders' half tracks with the standard anti tank gun of the day the 37mm PaK 36. By replacing the front machine gun with this useful light gun the panzergrenadier units could rely on a modicum of fire support as they charged