The King Tiger or Tiger II was developed in WWII as a heavy tank using the 88mm KwK 43 anti-tank gun. This gun barrel has the same diameter as the gun of the famous Tiger I but a longer barrel and a lager cartridge with propellent giving the round a higher muzzle velocity. An other but lager difference between the Tiger I and Tiger II is the shape of the armour. With the Tiger I the armour is welded together at straight angles placing the armour perpendicular to an incoming round. The Tiger II has armour at an angle from horizontal able to deflect an incoming round much like the Panther tank. Both Porsche and Henschel developed a turret for the King Tiger. 50 King Tiger's where equipped with the Porsche turret having a round front while the Henschel turret has a straight one. The King Tiger was in use from September 1944 until the and of the second world war. The King Tiger was made famous by it's deployment during the battle of the Bulge.
The Revell model
The model is quite a good one although not as good as their later releases. I added lifting eyes, engine covers and fasteners for the spare track links of metal. This is not my best model, check out Florin David's work for a better made example.