With the advent of the Panzerkampfwagen III Ausf.H (pictured here), a new cupola was added to the turret as was a circular vent on its roof; the rear face of the turret was a continuous plate, which the cupola did not intrude upon. The 5cm KwK38 L/42 fitted within a newly-designed external mantle was standard armament for most of these panzers; note the view ports on either side of the gun as well as the armored sleeve around the co-axial MG34. A new, pivoting driver’s visor was fitted, while the hull’s bow, glacis and superstructure all have bolted-on 30mm appliqué armor plates; note how they are fitted around the MG34, driver’s visor and tow points. A Notek head-lamp is mounted on the driver’s side fender, while the conventional head-lamps do not have slotted black-out hoods fitted. The visible marking next to the driver’s visor (a yellow inverted “Y”) with a single vertical stroke) represents the 2. Panzer-Division, after 1941. There also appears to be a small white outline square on the side of the turret, towards the front.
Source :
Book "Panzer Vor: German Armor At War 1939-45" by Frank V. De Sisto