Delivery horn for carbon dioxide fire extinguisher

C02 fire extinguishers are for use on electrical and flammable liquid fires. Carbon dioxide has been used in some capacity within fire extinguishers since the 1800s, but the discharge horn was patented in 1973 by Jack Winston of Brooks Equipment Co., in the USA.

The delivery horn expands carbon dioxide gas held within the extinguisher to create a mixture of the gas and snow. The horn can subsequently become extremely cold, so the extinguisher must not be held by the horn itself. It has gone on to be one of the most recognisable fire extinguisher designs.