The 8.8 cm KwK 36 L/56 (German: "8,8 cm Kampfwagenkanone 36 L/56" ) was an 88 mm tank gun used by the German Heer during World War II.
 This was the primary armament of the PzKpfw VI Tiger I tank.
 It was developed and built by Krupp.
The 745th Tank Battalion was an independent tank battalion that participated in the European Theater of Operations (ETO) with the United States Army in World War II.
 It was one of five tank battalions (all independent) that landed in Normandy on D-Day (6 June 1944).
 The battalion participated in combat operations throughout northern Europe until V-E Day.
 Unlike many independent tank battalions, which were attached to different units over time, the 745th was attached to the 1st Infantry Division for the duration of its combat operations in the ETO.
 It was inactivated in October 1945.
The 8.8 cm KwK 43 L/71 (Kampfwagenkanone —"fighting vehicle cannon") was an 88 mm 71 calibre tank gun designed by Krupp and used by the German Wehrmacht during the Second World War.
 It was mounted as the primary armament on the Panzerkampfwagen VI Ausf.
 B "Tiger II" and the 8.8 cm PaK 43, an anti-tank gun, was very similar in design and use albeit not mounted on tanks but rather on tank destroyers or deployed on the field.
The 509th Heavy Panzer Battalion (abbreviated "s.Pz.Abt.
 509") was a German heavy panzer abteilung equipped with Tiger I and later Tiger II "Königstiger" tanks.
 The 509th saw action on the Eastern Front during the Second World War.
 As with other German heavy tank battalions, it was never assigned to a single corps; but shuffled around as needed.
The Tiger I    was a German heavy tank of World War II deployed from 1942 in Africa and Europe usually in independent heavy tank battalions.
 Its final designation was "Panzerkampfwagen VI Tiger Ausf.
 E" often shortened to "Tiger".
 The Tiger I gave the Wehrmacht its first armoured fighting vehicle that mounted the 8.8 cm KwK 36 gun (not to be confused with the 8.8 cm Flak 36).
 1,347 were built between August 1942 and August 1944.
 After August 1944, production of the Tiger I was phased out in favour of the Tiger II.
German heavy tank battalions (German: "schwere Panzerabteilungen" ), were elite battalion-sized World War II tank units, equipped with Tiger I, and later Tiger II, heavy tanks.
 Originally intended to fight on the offensive during breakthrough operations, the German late-war realities required them to be used in a defensive posture by providing heavy fire support and counter-attacking enemy armored breakthroughs, often organised into "ad hoc" Kampfgruppen.
The Type 95 Heavy Tank was the final result of Japanese multi-turreted tank design, and was in commission during the time period between World War I and World War II.
 Modeled on German and Italian tank designs, this tank featured 2 turrets, the main armament being a 70 mm cannon, and its secondary front turret mounting a 37 mm gun and a 6.5 mm machine gun in the rear turret.
 Four prototypes were produced, in 1934.
The VK 36.01 (H) was an experimental German heavy tank during World War II.
 The VK 36.01 H was further development of the VK 30.01 H experimental medium tank.
 There were only 8 chassies and one of the tanks built, the chassies and tank were built by Henschel.
 At the time Henschel was assigned with developing a break through weapon that would help defeat the Soviets.
 Also other experimental heavy tanks and super-heavy tank were built, designed, and tested in Henschel.
 The development of the V.K. 36.01 H lead to the development of the Tiger I tank, a tank that played an important role in World War II.
 The tanks development lead to other tank development also.
 Then in 1942 the project was stopped in favor of the VK 45.01.
The L-11 76.2 mm tank gun was a Soviet tank gun, used on the earliest models of the T-34 Model 1940 medium tank and KV-1 Model 1939 heavy tank during World War II.
The 502nd Heavy Panzer Battalion (German: "Schwere Panzer-Abteilung 502" ) was a German World War II independent armoured battalion (German: "Abteilung") equipped with heavy tanks.
 The battalion was the first unit to receive and field the Tiger I.
 It fought on the Eastern front.
 It was one of the most successful German heavy tank battalions, claiming the destruction of 1,400 tanks and 2,000 guns.

Question: What was the size of the tank gun that was the primary armament of the German heavy tank of World War II deployed from 1942 in Africa and Europe usually in independent heavy tank battalions?
Answer: 88 mm