The Wpro extractor fan carbon filter CHF200/1 C00380118 offers a powerful absorbent action that protects against the spread of bacteria in the air. Your environment is healthier, which also reduce the risks of allergies. The performance is increased with the AC 40 quality charcoal. Its ability to absorb odours is 2 x greater than that of a traditional charcoal (AC 20). The auto-extinguish feature guarantees totally safe use (conforms to standard UL94: V-2). To ensure optimun performance it is recommended changing the filter every 3 months or when the indicator chage its colour.