Jagdtiger ("Hunting Tiger") is the common name of a German heavy tank destroyer of World War II. The official German designation was Panzerjäger Tiger Ausf. B as it was based on a lengthened Tiger II chassis. The 71-tonne Jagdtiger was the heaviest armored fighting vehicle used operationally during World War II and is the heaviest armored vehicle of any type to achieve series production. The vehicle carried a 128 mm PaK 44 L/55 main gun, capable of out-ranging and defeating any fielded Allied tank.