The Vk3.04K was a product of the country's war period, and in order to counter the armored forces of the enemy country, the country refurbished and modernized all the old tanks, including this Vk3.03K. The tank increased the armor thickness on the skirt plate and used new materials compared to the Vk3.02V. A pair of electro-optical interference systems and radio equipment were also installed, and an explosive reaction armor was installed on the skirt. The main gun was replaced with a 129 mm smoothbore gun, which can fire APFSDS ammunition. When using this type of shell, the theoretical maximum penetration depth can reach 580 mm.