The 1kg automatic powder fire extinguisher is mostly 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 to cover an area up to 1 square metre and will protect against fires involving flammable liquids, electrical equipment or wood, paper and material.