During the 2nd World War, the German Army used many 3 tons moderate vehicles to do tactical transport and logistics duties. The difficult operating conditions, provide on many fronts, made the traditional trucks unsuitable for off road purposes. Because only halftracks could operate in these conditions, a large amounts of trucks has been converted by removing their rear axles and putting new driveshafts according to songs. The Maultier SdKfz 3a halftrack was made on the basis of the popular Opel Blitz as the Maultier SdKfz 3b used the Ford V3000S truck framework produced in the Cologne production plant until 1941. The extreme freedom of this half-tracks Maultier made them perfect for the use of gun systems including the Flak 38 20mm.