I mostly use the CO2 and PM2.5 readings. The extra measurements are a nice bonus and the Wi-Fi function makes checking them easier.

There is a lot of information displayed at once, so it takes a little time to learn the layout. After that it is very convenient.

The monitor itself works well and the readings are clear. Wi-Fi setup took me a little longer than expected, but once connected the Tuya app has been useful.

The mix of gas, particle, temperature and humidity readings makes this a versatile monitor for different rooms.

I do not need laboratory-level detail. I mainly wanted an easy way to notice when indoor conditions are changing, and this does that well.

The screen is large enough that I can check the main values without picking up the device.

It gives a broader view of indoor conditions than the simple temperature and humidity monitor I used before.

I considered the standard version, but I am glad I chose the Wi-Fi model. Tuya access makes it much easier to check the readings remotely.

I use it near my air purifier so I can see how the particle readings change before and after running the purifier.

CO2, PM2.5, PM10, HCHO, TVOC, C6H6, temperature and humidity are all visible from one monitor. Very convenient.

The CO2 reading is the feature I check most often. When it rises, I know it is time to get some fresh air into the room.

It is compact and does not need much space. The Wi-Fi connection also means I can check it without being in the same room.

We use it mainly to watch CO2, temperature and humidity. I appreciate having the additional particle and VOC readings available too.

Even though it measures many things, I mostly just glance at the screen and AQI indicator. The layout is easy to get used to.

I wanted one device that could show CO2, particles and VOC-related readings together. This covers all of those plus temperature and humidity.

Once connected to Tuya, I can check the monitor without walking into the room. That is useful when it is placed upstairs.

PM readings rise when we cook, and this monitor makes those changes very easy to see. It reminds us to improve ventilation.

The color screen is one of my favorite parts. It is much easier to read than a small monochrome display.

I spend long hours working indoors, so being able to glance at CO2 and humidity is very useful. The app is convenient too.

The combination of CO2, particles, VOC-related readings and temperature/humidity makes this useful for everyday indoor monitoring.

I move it between rooms sometimes and it helps me compare CO2, temperature, humidity and particle levels around the house.

It does not take up much space on the desk, even though it shows a lot of different measurements.

I wanted a monitor that shows more than just CO2. Being able to watch HCHO and TVOC along with particles was one reason I picked this model.

I like that the 9BW adds Wi-Fi and Tuya Smart. It is much more convenient than checking the screen every time.

We leave it in the living room where everyone can see it. The screen is bright enough and the information is easy to check.

The PM2.5 and PM10 readings are especially useful when I am cooking or when outdoor air quality is poor.

Instead of keeping several monitors on the shelf, this gives me the main indoor air readings in one place.

The AQI indicator gives a quick picture of the room, and I can look at the individual values when I want more detail.

The display is easy to read and I like being able to see temperature and humidity together with the air quality information.

I can see the readings change when cooking, cleaning or opening a window. It is useful for understanding what affects the air indoors.

Setup was straightforward on my 2.4 GHz Wi-Fi network. The app makes it convenient to check the monitor from another room.

I keep this next to my desk and use the CO2 and particle readings to decide when to open a window or run the air purifier.