NO OZONE: All Arovec air purifiers are designed 100% ozone-free as it is a hazardous substance. This Purifier does not produce ions during air purification process. 4-Layered Filter System: Ultra-fine particles (smaller than PM2.5) are hazardous for human lungs. High Efficiency True HEPA Filter of this purifier removes pollutants as small as 0.3 microns that is well below the PM2.5. Filter must be changed at least every 6 months. Easily search for AV-P300-RF for affordable AROVEC replacement filter. PURE AIR: Removes allergens, smoke, volatile organic compounds, hazardous gases, dust, pollen, pet dander, mould, spores, and odours. Year-round comfort with pure air. SMART DESIGN: Reflects the realtime air quality using different colours. Automatically adjusts the purification level based on the detected air quality. Effective for rooms up to 30m2 (323ft2).