Detailed Description Cabin Air Filter ( automobile air filter , car air filter ) : Single-effected (white color): particle filtration Double-effected (mixed color of black & white): Particle Filtration & Polluted air filtration  Static nonwoven filter core (single-effected) / Activated carbon nonwoven compounded filter core(double-effected). Nonwoven soft frame. Filter core and frame are fixed by heat sealing machine. Single-effected filter can eliminate the inhalable particulate matter from outside such as the pollen/particle/microbe, etc effectively to purify the air inside the automobile. Double-effected filter can eliminate the inhalable particulate matter from outside such as the pollen/particle/microbe, etc, but also can get rid of the smog smell /toluene/sulfur dioxide such harmful gas effectively to purify the air inside the automobile.