Can't comment on accuracy or longevity, but it's a must have for anyone aware of how air quality can affect you. Especially since the Canadian wildfires are spreading cancer to the Midwest.

This did exactly what I expected and was super easy to set up, calibrate and use. I always leave it plugged in and on, but it has a rechargeable battery so it can be used without a power connection. It also displays temperature and humidity which is a bonus.

Little did I know how badly I needed this information. Easy to use, easy to understand. The battery lasts all day. The large, bright display is easy to read.

I used it in my brew room to monitor CO2 levels. Amazing how much the values increase when the room is closed! Glad to have this so I can keep track of when it gets very high.

If you are a truck driver you should have one of these in your sleeper cab. This could save your life if there is a steam leak or something is wrong with the central heating. I only wear this while I sleep. The battery typically lasts 5 nights before being recharged. Uses USB. It works exactly as it should. I even tested it by restricting the airflow. You can set an alarm to go off when the CO2 level you set is reached.

Air quality is very important at our senior center and this monitor provided more than we expected.

This little box packs a ton of features into a small screen. It quickly shows you humidity, temperature, air quality and CO2 concentration. Easy charging via the USB-C port. My main purpose is to keep it in a kegerator and help identify small CO2 leaks

Ordered it for my basement brewery to warn of CO2 leaks. The temperature was 10°F too high for the first few hours, possibly due to the heat generated while charging the battery? In any case, it now seems accurate (+/- 1F). The CO2 sensor is quite sensitive and seems accurate enough for my application. It's sensitive enough to detect an increase in CO2 levels after standing nearby for a few minutes, and I was surprised at how much higher (from ~460ppm to 650ppm) the concentration rose when I did last night prepared the dinner. To test the alarm function I assembled a 1 gallon jug, some random hoses and gas fittings and a CO2 syringe. Adding 7–8 milliliters of CO2 to the 1-gallon jug (about 460 ppm initially) increased the internal CO2 concentration to about 2400 ppm, which is well within error for this setup (one ml of CO2 should increase the CO2 concentration of one gallon). air by approx. 260 ppm). I am happy to add this to the other Inkbird products in my brewery. Addendum: I've had this in my (cellar) brewery for several days now. After venting the CO2 in my pressurized conical fermentor, it was nice to be able to check that the CO2 levels were still well within the safe range (~600ppm) and then returned to normal within a few hours. Very happy with the purchase.

really like this thing. I have it in my son's room so I can monitor temperatures and humidity. Easy to set up and calibrate. Just take it outside and hold the three buttons on top to calibrate it. The device came with dead batteries so I had to charge it but the battery life seems pretty good. Numbers are large and easy to read

don't know if this thing is scientifically accurate or not, but it measures what it claims to measure. Indoor CO2 levels are in the high 500 to low 600 degrees. Particles 002 to 005. I took the device into the kitchen, closed the door, put it near the gas stove and put the kettle on. When the water boiled, the CO2 value rose to over 1500. The fine dust remained low. Then he went into the bathroom, closed the door and lit a match. The particle level rose to over 100 in less than a minute and the alarm went off. CO2 stayed in the 500s. When the exhaust air fan was switched on, the particles fell back to 002 and the CO2 value to high values in the 400s. The temperature is a few degrees higher, probably because the device generates some heat. It comes with a charger and cable.