The Winix 5530 features a 4-stage air purification system, this unit removes 99.99 percent of airborne particles as small as 0.01 microns in size. Winix's PlasmaWave Technology may help to reduce the presence of airborne pollutants and impurities. The unit's built-in Smart Sensors detect and monitor the quality of air in your environment and provides a visual representation of your current air quality. When in Auto Mode, the unit automatically adjusts fan speeds to ensure efficient and cost-effective cleaning. Sleep mode is automatically activated when the room is darkened, providing quiet, energy-efficient operation.