The 1kg automatic powder fire extinguisher is most popularly used for protecting small boat engine compartments. It has a heat sensitive (79 degrees centigrade) sprinkler bulb at the base and, when a fire reaches that temperature, the bulb bursts and will discharge the powder within the compartment. A 1kg auto is good for an area up to 1 cubic metre and will protect anything against small flammable liquids, electrical or wood, paper and material fires.