Review on Monitor air quality, CO2 concentration, formaldehyde, volatile organic substances. Temperature and humidity indicator. by Vassil Filimonov ᠌

Different pros: A very interesting toy, I bought it to understand the level of carbon dioxide in different rooms . quickly identified the places where ventilation is needed Its cons: The instruction is in many languages, but not in 2022n . of course, everything is clear, but how incorrect it is