I added a high end air purification system to cover my entire home. Even though the thermostat and unit has indicators of the current air quality in my home it does not come close to the accuracy of this little unit. App on your phone to control and track all activity in your home. Very easy to set up and really works great. Can even sync it to your smart thermostat to control the fan if air pollution in you home gets really out of hand with or without the purification system.
Great sensor. I never realized how much my air quality impacts overall health until I started using the sensor/app. Definitely going to change my air filters more often.