The Levoit Core 400S Smart Air Purifier, is the efficienct air purifier to clean a whole room properly. AirSight Plus technology scans the surrounding air for airborne particles as small as 0.3um, this air purifier focuses on real-time home conditions – this is more than just having an air purifier. Levoit engineers designed the air purifier’s internal structure to provide powerful air purification while maintaining noise levels as low as 24dB.