Panzerwerfer is the name for two different types of half-tracked multiple rocket launchers employed by Nazi Germany during the Second World War. The two self-propelled artillery vehicles are the 15 cm Panzerwerfer 42 auf Selbstfahrlafette Sd.Kfz.41 (based on the Opel Maultier, or mule, half-track) and 15 cm Panzerwerfer 42 auf Schwerer Wehrmachtsschlepper (or Panzerwerfer auf SWS). Some Panzerwerfers had a machine gun mounted above the cab. It was known as the Moaning Minnie by Allied soldiers for the distinctive noise the rockets made when fired, similar to the Nebelwerfer.