Fire Extinguisher 1Kg Dry Powder ABC 40% with one seam vessel and Pressure Gauge Safety Release Valve. METALLIC BRACKET INCLUDED. Fire extinguishers with a Class A rating are effective against fires involving paper, wood, textiles, and plastics. Fire extinguishers with a Class B rating are effective against flammable liquid fires. Fire extinguishers with a Class C rating are suitable for fires in “live” electrical equipment.