Coway AP-0510IH Tower Air Purifier with HEPA Filter Modern: Compact by design, but equipped with cutting edge features ensuring your living space is protected True HEPA: Cleanses 99.97% of indoor air, using a 4-stage filtration system with a Pre-Filter, Carbon Filter, Air Ionizer, and a True HEPA filter Air Quality Indicator: Intuitive Air Quality Indicator uses particle sensor technology to monitor the air with vivid color changes Filter Change Indicator: When it's time to change the filter, the Coway Filter Change Indicator will light up Smart Mode: Fan automatically adjusts airflow when pollutants are detected, providing peace of mind that indoor air quality is always monitored. Stylish tower design requires minimum space and provides maximum efficiency 3-stage filtration : pre-filter + carbon filter + 3-year hepa filter effectively eliminates pollutants Long-lasting 3-year hepa filter fights dust, smoke, pollen, mold and pet dander Filter change indicator : always stay fresh by changing filters on time Aham certified and energy star