1,real-time display air ppllution index; 2,the air tester is test VOC, dust bacteria, stink,weat, etc; 3,display the calendar. 1,newest ... calendar desigen:display year, moth, day, time, week;2,the air tester is test VOC, dust bacteria, stink,weat, etc;3 ... bacteria, dust, stink, sweat, etc. VOC is test the organic volatic gas in the air, mainly tolunene, xylene etc(home decoration,volatile gas ...