Structural Design of Double-Rotating Air Purification Duct:Portable car air purifier adopts a 4-stage filtration system. High-efficiency filter layers remove 99.9% of harmful gaseous substances such as car exhaust fumes, chemicals emitted by plastic materials, and other odor-emitting substances (volatile organic compounds (VOCs), toluene, and formaldehyde are even more down to 0.1 microns in size Energy Saving & High Efficiency & Silent Operation:Small volume and high-performance fan, with speed up to 5300 RPM, only 4W power, and up to 60000 hours of service life. It only takes 6 minutes to filter at a time, purifying up to 10 times in 1 hour, operating virtually silently