Received the unit quickly and works as specified. I have not validated the numbers for each sensor item yet, will try to do that soon.

it takes 2 minutes for the hcho/tvoc sensor to start measurements. co2 and pm2.5 is instant. hcho/tvoc has a sensitivity of 6ug/m^3.

The numbers run) normally, the screen is slightly at right angles dim, but from the top to the bottom you can see the norms

It works well, although it's hard to check the accuracy of the values, unless you have two.

The product corresponds to the description. The device is working. On CO2 reacts quickly.