Bests & Worsts Reviews from Amazon

I've been using this device for over a year and found it to be the most accurate of the 3 inexpensive air quality devices I have. I also have a Dylos Pro which, at twice the price, is more accurate but lacks wifi features. The AirVisual Pro is mainly useful for measuring particulate matter and can be placed either indoors or outdoors. Used outdoors it can help you decide when to open windows, and indoors it can also help you decide when to run air filters. We've had ours outdoors, but under a roof out of the rain and sun, for over a year and it still runs and looks like new. It also reports ozone concentrations broadcast from the nearest municipal sensing station, which is useful too. It does not measure ozone nor does it report or measure VOC levels. For comparison, we also have a Foobot and and an Awair. Both of those have features missing from the Airvisual Pro, such as VOC measurement and IFTTT compatibility so you can, for example, set those to turn on air filters automatically when the dust count gets high. I would hope AirVisual will add these features one day. The problem with Foobot and Awair is that their dust sensors are very inaccurate and inconsistent and the VOC sensors aren't so great either. The Dylos Pro beats all of them in measuring particulate levels. It's the only one that can give you an idea of PM2.5 levels vs PM10 levels which is useful for distinguishing pollen from pollution, for example. But the Dylos is more expensive and not practical as a 24-hour monitor the way the AirVisual is. Each of the 4 products has its use and none is ideal, but the AirVisual Pro is probably my favorite in that it does what it is designed to do, inexpensively, and without misleading false readings.