Datasheet:
MH4-R

It measure the air quality and give you the “parts per million” (unit ppm) back.

Sensor is tested and working with the following:

mkdir co2
cd co2
git clone https://github.com/IT-Berater/mh-z19.git
cd mh-z19
./setup.sh

sudo python -m mh_z19
{‚co2‘: 668}