CO2 Carbon Dioxide Detector, Indoor Air Quality Monitor 4-in-1 Portable CO2 Monitor, Tester for Carbon Dioxide, Temperature & Relative Humidity, CO2 Meter with Alarm, for Home, Car, Grow Tents, Travel

It's inexpensive, and I'm sure it's not incredibly accurate, but if you're looking for a cheap way to tell if the room you're in has too many people rebreathing each other's air, I'd say this is it. Very useful to demonstrate to me the reason to mask up on public transport, and to tell whether the meeting room I'm entering is going to put me into a deep sleep while simultaneously threatening my continued health.

This product can monitor the CO2 concentration for a room which is a life changer to me. It provides indication to all the potential causes impeding the living quality of a room, directing you to solve the issues rapidly.

I'm going to give the most honest review I can about this. It's ok at best because of a few reasons. First one is because it needs to be plugged into the charger consistently. You will only get about 18h of run time without it being plugged in. Secondly it's about + or - %10 inaccurate with its readings. Only reason I know this is because I have multiple different sensors just so I can verify the conditions at different points in the room. This one was the only one showing weird numbers so I lined all of them up next to each other for a day to see. All of the others shown similar numbers but this one was off by about %10 with everything, but the temperature was right tho. The co2 and humidity are off a bit because I have 3 other units that show similar numbers but this one doesn't. Plus it's delayed with its readings. I blew my breath behind all of them I has set up and this one just responded the worst. It took awhile to even detect more co2 in the air. I wouldn't buy this one again but to be fair my other units are 3x as much. I was being cheap when I got this SMH. I got it for a plant grow space but kind mad I didn't spend 20 more dollars on a better one.

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Mixed feelings about the accuracy but the battery life is bad.These will not last more than about 7-6 hours before needing to be charged.

This is a great monitor and is very accurate. I would like the alarm to be a little loader, but otherwise, it is exactly what I need for my tiny home since I run several propane appliances and a wood-burning stove.

If you blow on it, the co2 goes up and an alarm goes off.

We returned one because it constantly recalibrates itself (indoors) for no apparent reason, resulting in inaccurate readings.The second one does the same. Will be returning it too.2 stars for accurate readings when calibrated, but I don't have the time to recalibrate it outdoors every few days.