The third, and likely most effective kind of tank destroyer was the unturreted, casemate-style tank destroyer, known by the Jagdpanzer term in German service, or Samokhodnaya Ustanovka in Soviet service for their own designs. These generally featured a heavy gun mounted on an older or then-current tank chassis, with the gun pointing forward with a limited degree of traverse. Casemate tank destroyers often had the same amount of armour as the tanks they were based on. The removal of the turret allowed for greater room to mount a larger gun with a larger breech and leave room for crew. Many casemate tank destroyers either originated as, or were dual-purpose vehicles with the duty of a self-propelled gun, which share many (but usually not all) of the same features and layout. Some examples are the German Sturmgeschütz III – the most-produced German armored fighting vehicle of WW II — and the Soviets' SU-100, itself based on the T-34 tank's hull and drivetrain.