High-efficiency filtering function: Equipped with a 4-Stage Filtration system including Pre-filter Activated Carbon Filter TRUE HEPA Filter Fabric Layer.This filter can remove all air contaminants as small as 0.3 microns with zero harmful Ozone emission. can effectively capture smoke produced in wildfires It also effectively captures exhaust gas emitted by automobiles in the air ultrafine dusts around your living space. It is perfect for pet owners babies children the elderly or anyone wanting to improve the air quality.It is recommended to replace your filter every 6-8 months depending on the use and air quality.