?Efficient Purification: adopts HEPA filter, the 4-stage filtration helps you to improve air quality and capture 99.97% of pollen, dust, pet dander, smoke, mold spores, household odors, depth-type filtration the PM2.5. It ensures a high efficient air filtration and clean air up to 90m³/h, and creates a healthy environment by eliminating bacteria with breathing problems or allergies. ?True HEPA Filter: it can remove more than 99.97% of the particles with a diameter of 0.3 microns (1/200 of the hair diameter) or more, which is the most effective filter media for pollutants such as smoke, dust and bacteria. Please remove the plastic package from the filter before using. ?Ultra Quiet: the working decibel is less than 50dB, and won't disturb you in your office or bedroom. Especially a perfect choice for small size room. ?Multi Function: 3 level speed control among the circulation settings; An optional automatic shut-off timer of 2/4/8 hours of continuous use; Nightlight with 2 brightness; Red flashing indicator when need to replace filter. ?Economic Way For A Healthy Living Environment: its working power is only 35w power and won't waste much electricity. It is suggested to replace the filter every 3-6 months based on the the air quality in your area. (For more filters, please search B07QZWK6HC on Amazon)