German armaments firm Krupp designed Panzer IV's suspension. Being specialist in designing railroad locomotive and rolling stock, their cross-country chassis expertise was evident in the quarter elliptical leaf-springs of each bogie wheel-track assembly. Krupp - en.wikipedia.org/wiki/Krupp

Squeeze tub on right fender is grease gun to lubricate wheel assembly, mushroom-like apparatus next to headlight is a Notek driving light, brown box stored smaller tools, wire cutters mounted on the fender. Ribbing behind the driver is a water-deflection plate to channel water around the turret during quick river crossings. Notek head light - sdkfz7.free.fr/enoteksdkfz11.htm | Notek tail light - sdkfz7.free.fr/enotekpz4.htm

End of WW2 saw numerous late-model Panzer IVs captured by Allies. French took their Panzer stockpile and sold it to Middle Eastern countries. When Israeli 1948 War of Independence broke out, Syrians deployed their Panzer IVs as fortified pillboxes. Israeli forces also purchased ex-German equipment such as Machinengewehr 34 (MG-34) machine guns from Czechoslovakia and augmented it into their mobile wheeled and halftrack formations. 1948 Arab-Israeli War - en.wikipedia.org/wiki/1948_Arab-Israeli_War

After 1939 Polish Campaign, Germans reorganized their Panzer Divisions, all Light Divisions were upgraded to Panzer Division status, thus creating 6th, 7th, 8th, and 9th Panzer Divisions. Each division possessed a Rifle Brigade, Artillery Regiment, Anti-Tank Battalion, Anti-Aircraft Battalion, Engineer Battalion, Reconnaissance Battalion and Communications Battalion, making Panzer Divisions an integrated fighting formation. List of German divisions in WWII - en.wikipedia.org/wiki/List_of_German_divisions_in_WWII

Existing 1940-era German Panzer Divisions (ex. 1st, 2nd, 3rd, 4th, 5th and 10th) had their Panzer Regiments upgraded to four Panzer Abteilungs ( armored battalions). Each Panzer Regiment and Panzer Battalion had their own Command Company. Company units composed of 5 Panzer II tanks, troop transports, and towed artillery. Each Panzer Battalion composed of 3 companies. 1st company was equipped with 5 Panzer IV and 10 PzKpfw I and II. 2nd and 3rd company were equipped with 5 Panzer III and 17 Panzer I and II. Panzer Division - en.wikipedia.org/wiki/Panzer_division

By 1941 invasion of Soviet Union, Panzer I and Panzer II tanks were withdrawn from frontline service, Panzer III tanks continued its service but was limited in firepower upgrade and armor protection against Soviet T-34 tanks, leaving Panzer IV chassis as only viable upgrade before introduction of German heavy tanks such as Tiger, Panther, and Maus. Panzer III - en.wikipedia.org/wiki/Panzer_III