Original Xiaomi Anti Formaldehyde Filter for Xiaomi Air Purifier 1 and 2 is supplied by the top 3 US air purifier manufacturers, the filter combines an aerodynamic 360å¡ cylindrical design with a powerful triple-filter consisting of primary, HEPA and activated carbon layers. Easy to use and replace. Activated carbon absorbs harmful gases that HEPA is unable to filter. Mi Air Purifier is combined with an anti-formaldehyde formula that effectively absorbs harmful chemicals such as formaldehyde, benzene and ammonia, as well as odors and smoke. Home renovations and other activities may release substances such as formaldehyde, benzene and TVOC, which can cause harm at high densities. Mi Air Purifier's coconut activated carbon filter absorbs hundreds of harmful substances in these situations, keeping your home clean and your family healthy.