I like my Netatmo. I see that it costs $200 on Amazon for main module + you can connect 3 additional ones for other rooms — they cost $86 each. It shows CO2 (no

I like my Netatmo. I see that it costs $200 on Amazon for main module + you can connect 3 additional ones for other rooms — they cost $86 each. It shows CO2 (notifies when it's high on smartphone), temperature, relative humidity and noise level.