Continued development of the reconnaissance tank concept led to the much up-armored Ausf. J, which used the same concept as the PzKpfw IF of the same period, under the experimental designation VK1601. Heavier armor was added, bringing protection up to 80 mm on the front and 50 mm to the sides and rear, with 25 mm roof and floor plates, increasing total weight to 18 tons. Equipped with the same Maybach HL45P as the PzKpfw IF, top speed was reduced to 31 km/h. Primary armament was the 2 cm KwK38 L/55 gun. 22 were produced by MAN between April and December 1942, and seven were issued to the 12th Panzer Division on the Eastern Front.