They are divided into simple fire extinguishers, portable fire extinguishers, and wheeled fire extinguishers. The simple ones come in 380mL and 520mL, suitable for homes, cars, chemical inspections, and other small places. The portable ones are 3L, 6L, and 9L, good for chemical transport, offices, factories, and public spaces. The wheeled ones come in 25L, 45L, and 65L, ideal for large factories, warehouses, train stations, and charging station areas.