In the second half of 1934, the Germans started developing a tank designated as the Verbesserten Nb.Fz. The Rheinmetall company was responsible for its design. The vehicle was supposed to weigh 17-18 tons. Its armament consisted of a short-barreled 75 mm gun and a coaxial machine gun. Another machine gun was placed on a small turret at the front of the hull. Higher-density configuration with the transmission in the front helped dramatically reduce the hull length. There were also plans to use a special V-shaped 10-liter 12-cylinder Maybach HL 100 TR engine with 300 h.p. of power. Rheinmetall produced a life-size wooden mockup, and later a chassis out of construction steel. Many improvements were made to the latter, but it did not become the base for the mass-produced tank.