First large scale production of this type. Wider tracks, larger sprockets, and hull stowage bin. Increase in side and rear armor from 15mm to 20mm. Late production vehicles had armor plate bolted and welded to turret and hull front. The front superstructure plate was stepped and the radio operator was moved back further than the driver. Hull MG was installed.
Some of the last produced had 30 mm plates bolted and welded onto the hull superstructure front and 20 mm to the sides.
Had external mantlet.
In 1943 some were upgraded to 75 mm KwK L/48. 16 chassis were converted to bridge laying tanks, 2 chassis to self-propelled guns, and a Munitionsschlepper for the Karl.