LIFAair LAC90 car air purifiers with two -layer filer and dual fans, which improving both air cleaning rate and filtration area that are suited for larger cars. The two-layer filter offers comprehensive cleaning.The particle filter layer catches the dust, allergens, and PM2.5 particles, while the second stage active carbon layer absorbs gaseous contaminants and removes odors. This device come with a smart controller built in with PM2.5 sensors that monitor your car indoor air quality at all times. If the levels of PM2.5 increase, the purifier turns on. The LAC90 offer the most sophisticated purifying & monitoring system to date. An intelligent innovative system designed to empower you and your family to breathe fresh air while on the go.