The Nebelwerfer ("Smoke Mortar" literally "Fog thrower") was a World War II German series of weapons designed to deliver chemical weapons. They were initially developed by and assigned to the Wehrmacht's so-called Chemical Troops (Nebeltruppen). This weapon was given its name as a disinformation strategy designed to lead spies into thinking that it was merely a device for creating a smokescreen. They were primarily intended to deliver poison gas and smoke shells, although a high-explosive shell was developed for their Nebelwerfers from the beginning. Initially two different mortars were fielded before they were replaced by a variety of rocket launchers ranging in size from 15 to 32 centimetres (5.9 to 13 in). The thin walls of the rockets had the great advantage of allowing much larger quantities of gases, fluids or high-explosive to be delivered than artillery or even mortar shells of the same weight. Nebelwerfers were used in every campaign of the German Army during World War II with the exception of the Balkans Campaign. One rocket was even adapted for air-to-air use against Allied bombers.