Dyson Purifier Cool air purifier PC2 De-NOx TP12 (White/Gold), 2-in-1 purifier fan,Captures allergens and up to 99.9% of viruses10, such as COVID-19 virus11, coverage in a 81m³ room, Advanced air purification automatically captures 50% more NO2.1 Precisely detects and destroys formaldehyde, permanently. Cools you with powerful airflow.we recommend replacing the HEPA+K-Carbon filter every 12 months9 (based on 12 hours a day of use) You'll be notified via the MyDyson™ app or LCD screen when it's time to replace the filter.