The Wpro extractor fan carbon filter AMC 145 C00384667 features a powerful absorbent action that protects against the spread of bacteria in the air, providing you a healthier environment, and reduce the risks of allergies. Plus, the AC 40 quality charcoal odour absorption performance is 2 x greater than that of a traditional charcoal (AC 20). It also guaranees total safe use with the auto-extinguish feature (conforms to standard UL94: V-2). To ensure optimun performance, it is recommended changing it every 3 months or when the indicator chage its colour.