The Panzer III Ausf.F succeeded the Ausf.E as the next version of the Panzer III and was essentially a refined version of its predecessor.
Panzerkampfwagen 38(t) Ausf.B-S- Tank Encyclopedia
Panzerkampfwagen III Ausf.E (Sd.Kfz.141) - Tank Encyclopedia
Panzerkampfwagen III Ausf.E (Sd.Kfz.141) - Tank Encyclopedia
Panzerkampfwagen III (flamm) - Tank Encyclopedia
Panzerkampfwagen III Ausf.E (Sd.Kfz.141) - Tank Encyclopedia
The Panzerkampfwagen III main battle tank (1937)
Panzerkampfwagen-I (1934)
Panzer III, World War II Wiki
File:Sd Kfz 141-2 Panzerkampfwagen III Ausf N.jpg - Wikimedia Commons