Umgebaute Flammenwerfer 40 (Converted Flamethrower 40) is a backpack flamethrower

Flamethrower

A flamethrower is a mechanical device designed to project a long controllable stream of fire.Some flamethrowers project a stream of ignited flammable liquid; some project a long gas flame. Most military flamethrowers use liquids, but commercial flamethrowers tend to use high-pressure propane and...

 converted to shoot a powerful jet of water solution of CN gas

CN gas

Phenacyl chloride is a substituted acetophenone. It is a useful building block in organic chemistry. Apart from that, it has been historically used as a riot control agent, where it is designated CN.-Preparation:...

 as a riot control device. The device was first used by the Swiss police in 1940.

Some Converted Flamethrower 40s were loaned to the German police for use at the protests against building the Runway West (Startbahn-West) at Frankfurt-am-Main in West Germany

West Germany

West Germany is the common English, but not official, name for the Federal Republic of Germany or FRG in the period between its creation in May 1949 to German reunification on 3 October 1990....

 in 1979. Some police still use them, for example in Aargau

Aargau

Aargau is one of the more northerly cantons of Switzerland. It comprises the lower course of the river Aare, which is why the canton is called Aar-gau .-History:...

 in Switzerland

Switzerland

Switzerland name of one of the Swiss cantons. ; ; ; or ), in its full name the Swiss Confederation , is a federal republic consisting of 26 cantons, with Bern as the seat of the federal authorities. The country is situated in Western Europe,Or Central Europe depending on the definition....

.