The E-5 was supposed to be 5-10 tons in weight and form the basis of a family of light tanks, reconnaissance vehicles, casemate-form turretless Jagdpanzer-style tank destroyers and armored personnel carriers. So far no evidence of this tank is found in primary sources, and is quite likely to be a fanboy design of recent origin. The E-Series program was proposed in May 1942 by Dipl Ing Heinrich Ernst Kniekamp, Chief Engineer of Waffenpruefamt 6. In April 1943, Heereswaffenamt (Army Weapons Office) accepted his program and ordered a number of manufacturers to begin planning and development of the Entwicklung (development) / Einheitsfahrgestell (general purpose chassis) Series.