The filter features active carbon for absorbing harmful pollutant, as well as a self cleaning function which decomposes and eliminates them with LED light using the photocatalytic technology. This cycle of operation allows the filter to restore itself and achieve long service life. 3-layer-filter reliably captures invisible pollutantsFL-C320 consists of 3 layers: 1) Pre-filter (for dust, pet hair) 2) HEPA type filter (for PM2.5, pollen, bacteria, virus, mites, mold) 3) Self-cleaning active carbon filter (for VOC, smoke, odour, chemicals) Specifications Filter for cado air purifier LEAF 320i (AP-C320i) and LEAF 200 (AP-C200): sold separatly 3 Layer filter: Pre-filter, HEPA type filter and self-cleaning active carbon filter Capturable subtsances: PM 2.5, dust, pollen, pet danders, tobacco smoke, VOC, formaldehyde, etc. No ozone is emitted Filter life is 6 months to 1 year Product Dimensions 20 x 20 x 26.7 cm Weight: 500 g Colour: Grey