Aranet4 CO2 Monitor
I discovered that the CO2 levels where I slept were at 2,300 ppm, whereas the level in fresh air is around 420 ppm. 👩❤️👨 Also, two people in a room = 2x of CO2 💨 So, I started sleeping with the window open, which reduced the CO2 level to 500 ppm. ☺️ Now, I sleep for 8 hours straight and wake up feeling refreshed and energized.