The Vollketten 30 were two series of tank designs by Germany in World War II, originally intended as heavy 'breakthrough' tanks, but later switching completely to designate medium tanks to succeed the Panzer III, IV, and the planned VK 20 series tanks. These were requested in response to the Soviet T-34 and KV-1 tanks, with far heavier armour and armament than the mobile armoured vehicles fielded by the Wehrmacht at the time. Many German companies submitted projects, including Maschinenfabrik Augsburg-Nürnberg (MAN), Daimler-Benz (DB), Henschel, and Porsche. The winning entry tanks would go on to become the famous Tiger I and Panther tanks, and capable opponents to the T-34 if ultimately too late and at too small of a scale to affect the course of the war.