This CO alarm is very nice to look at. Everything you need to know about the feature is clearly displayed on the 3-inch round screen. A large and brightly lit display shows you the amount of carbon monoxide present, as well as the temperature and humidity in the environment. Very handy if you are a herpetologist or need to keep your tarantula in optimal conditions. But is what is shown correct? The humidity shown matched exactly the amount shown on my smart thermostat. According to the thermometer I trusted, the temperature was a little off. I was looking for a method to calibrate, but unfortunately this device does not support this function. Exact temperature accuracy doesn't matter much - detecting carbon monoxide is what really counts. My unit reads ZERO ppm carbon monoxide - that's reassuring. Since this unit is so portable and can be charged with a standard 5V USB phone charger, I will take it with us on our small RV trips. The RV has a propane heater, stove and refrigerator, so an O2 monitor is a must. What I like about this CEKKIENA carbon monoxide alarm: - The look and feel - The portability and ease of use. - The display can be switched to "always on" or "off after ten minutes". - Color coded light indicating different levels of CO detected. (Green = OK, Yellow = 100-200ppm, Red + Siren Alert = over 200ppm) - Celsius or Fahrenheit display - 90 hours of use on one charge. Cons: Not really negative, but this unit cannot be wall mounted as the USB port is on the back of the unit. There is a fold-out stand on the back of the unit so it can be placed on a shelf, countertop or mantel. When traveling with the mobile home, it should be in a drawer. I'm really glad I have this...a little bit more security for my family - and I look forward to using it in the RV.

Easy to read, battery lasts a long time and charges quickly. Work as a home inspector and check for Carbon Monoxide and Water intrusions so having a device that does both is great. Have had other CO2 sensors and always reading wrong, this one is very accurate.

Our old one recently died so bought this one to try. Love the 3 in 1 ability as we only had 1 thermometer in the house and temperatures always seemed lower on the second floor so this is definitely convenient.

It was a great product and did what I needed it to do- detect carbon monoxide- which it didn’t… I was pretty sure I didn’t have any carbon monoxide in my home as I don’t have any gas engines or anything that makes carbon monoxide. I just purchased a home with a built in carbon monoxide detector in the alarm system… which would go off periodically for no reason as far as I could detect as again I don’t have any gas engines or garage connected to my home where one would park a car for instance… so for peace of mind and because I have guests staying in my home, I purchased for peace of mind. It was a great instrument- easy to read and I trusted it as I brought it out to my car and calibrated it as it did show carbon monoxide when by the car exhaust- just none in the home. I live close to a metropolis and I was convinced my home detector is picking up smog- and looks like I was right if it picks up anything - could just be a glitchy product on the home alarm system…

The display is easy to read, and it seems to give an accurate reading. Perfect size. Taking on my next vacation.

We keep this in the kitchen. Probably use the temp readout more than the CO readout.

The charging cable sticks straight out the back, so you can't hang it on a wall while charging. We like to leave it plugged in so that's an inconvenience.

This is a nice little compact CO monitoring device. It fits in my jacket pocket because I bring this with me when driving in the car. The round device would have to lie down flat if it didn't have a handy little kickstand which also protects the set and adjust buttons on the back when its in the stored position. Meaning it won't change the settings if it bounces around in my handbag. The display is bright and has large enough numerals to be able to read it from a distance and you can also turn off the display so it doesn't disturb your sleep while protecting your life. The alarm siren is loud and could wake the dead which is what it needs to do if you are sleeping or unconscious when overtaken by deadly fumes. This is my new little sidekick that warns me of impending doom.

I like the fact that this little device has multiple functions. I have used it for about one week and I am satisfied with its user-friendly interface and safety features. It is worth the money.

This is great for travel & home & vehicle. It is accurate, the humidity is useful & the Carbon Monoxide detection is literally something that could save your life anywhere. The temperature is great especially at hotels that you can't set it to a number. When you can set it to a number (Celsius or F it accurate for both). Put a magnet on it for my magnetic mount in my car if needed but use it mostly for travel. Wish it was USB-C charging instead of micro-USB but not a deal breaker as so many of my other stuff is micro-USB. This is extremely useful so far for travel love it.

This is nice. Although I am not interested in the amount of humidity, I am interested in a Carbon Monoxide and Smoke Detector for our Airstream. We checked it out with the smoke and works and if the carbon monoxide alarm is as loud it will be great. It has a nice clear design and it is pleasing to look at.