HR-903 Smart 3-Stage Filtration Air Purifier, Negative Ion Generator with Formaldehyde Removal, Silent Sleep Mode for Home Bedroom 30㎡： HR-903 smart air purifier is designed for household indoor air cleaning, specially developed to solve indoor pollution troubles such as formaldehyde, PM2.5, second-hand smoke, dust, mold and peculiar odor. Equipped with three-layer composite filter including high-density pre-filter, HEPA filter and cold catalyst activated carbon filter, it can capture tiny particles as small as 0.02μm, effectively decompose formaldehyde, benzene and other harmful VOCs. Built-in negative ion release function releases fresh negative ions to refresh indoor air; turbo 3D circulation fan delivers high-efficiency airflow for full room purification within coverage of 30 square meters. It supports 3 adjustable wind speeds,1-8 hours timing function, temperature sensor real-time monitoring and ultra-quiet sleep mode, bringing noise-free clean air during rest. With low power consumption energy-saving design （30 hours per kWh）,50Wlow rated power runs all day without high electricity cost, simple one-touch control panel for easy operation, ideal for bedroom, living room, study and small apartment.