Panzerkampfwagen VIII Maus ("mouse") was a German World War II super-heavy tank completed in late 1944. It is the heaviest fully enclosed armoured fighting vehicle ever built. Only two hulls and one turret were completed before the testing grounds were captured by the advancing Soviet forces. These two prototypes – one with, one without turret – underwent trials in late 1944. The complete vehicle was 10.2 metres (33 ft 6 in) long, 3.71 metres (12 ft 2 in) wide and 3.63 metres (11.9 ft) high. Weighing 188 metric tons, the Maus's main armament was the Krupp-designed 128 mm KwK 44 L/55 gun (55 calibers long barrel), based on the 12.8 cm Pak 44 anti-tank field artillery piece also used in the casemate-type Jagdtiger tank destroyer, with ...