It tells the air quality around you according to the concentration of PM10(Particulate Matter Less than 10㎛). 0~30 ㎍/㎥: good 31~80 ㎍/㎥: not bad 81~150 ㎍/㎥: bad 151 ㎍/㎥ ~: very bad * Currently, this service is only available in Korea.