The Kliment Voroshilov Model One, also known as the KV-1, is a Soviet Army heavy tank deployed at the beginning of World War II, equipped with the same 76.2mm gun as the latter T-34 while being around ~15t heavier.
Its armor was enough to survive the majority of Germany's AT guns during the early part of the war at the Eastern Front. Gradually replaced in later years of the conflict (but continued to be used in some units unitl the end). A number of derivatives were also built on the hull, such as the KV-2 (armed with a 152mm howitzer).
This tag implicates tank (learn more).