I just opened mine and it's pretty sweet. I breathed on it and the CO2 shot up and an alarm went off. Freaked the hell out of my poor daughter's dog, but it works awesome, . Thanks @Inkbird
It saved my ass when I got it. Wife seen the levels rising when we ran the bath, I looked into it and realized the hot water tank was backflowing the exhaust into the house. Without it, I wouldn't have noticed so quickly.
This multifunctional air quality monitor can accurately detect the current CO2 concentration, temperature, and humidity in the air. It can help you understand grow tent air quality at a glance.