8-cm Raketen-Vielfachwerfer auf Panzerwerfer 42 - German mobile multiple launch rocket system on the chassis of the well-known Opel Maultier half-track, designed in 1943. It was derived from the Soviet BM-8 Katyusha, with some improvements to both the rockets and the launcher. Vehicles of this type were delivered to combat units, mainly to SS divisions, from 1944; however, they were very small in number, and their usage was very limited. German soldiers nicknamed these machines the 'Himmler Organ' because of the unique noise heard during rocket firing, analogous to the nickname for the Soviet Katyusha, 'Stalin Organ'.