KV1 - Heavy Tank

The Kliment Voroshilov (KV) tanks were a series of Soviet heavy tanks named after the Soviet defense commissar and politician Kliment Voroshilov, who operated with the Red Army during World War II. The KV tanks were renowned for their heavy armor protection during the early stages of the war, particularly during the first year of the German invasion of the Soviet Union. In certain situations, even a single KV-1 or KV-2, supported by infantry, could halt German formations. 

The KV tanks were practically immune to the 3.7 cm KwK 36 and howitzer-like, short-barreled 7.5 cm KwK 37 guns mounted on the early Panzer III and Panzer IV tanks, respectively. Until the Germans developed more effective guns, the KV-1 was invulnerable to almost any German weapon except the 8.8 cm Flak gun.