The Xiaomi Mijia Honeywell Fire Alarm Smoke Detector used for smoke detection in the air. Any fire is accompanied by smoke, and this detector will turn on a loud alarm in that case, and also (if it was properly set), it can send an alarm to your smartphone. Additionally, your smart home can do some actions when the smoke is detected.

You can install the battery (CR17450) and mount this detector to the ceil, then you will get the fire alarm in the room with a loud sound. Also, you can connect it to the smartphone using Mi Home app (Bluetooth needs to be enabled in the smartphone). In this case, you will be able to control the smoke detector from your phone and get notifications, but only when you are located in a few meters from the smoke detector.

You will get much more functionality when you connect this detector to the smart home gateway. Because this is bluetooth version, you need to use gateway, which is compatible with Mi Home app, and can work with Bluetooth devices, for example, Xiaomi Gateway 3. On this page you can select filter on top "For Mi Home app only" and choose gateway you want (with Bluetooth function). For now, there are many smart devices that have built-in gateway function, for example, this camera.

Then Honeywell Fire Alarm Smoke Detector connected to your smart home via gateway, you can add automatic actions in the Mi Home app on a case if smoke is detected. Also, you will get notification to your smartphone even you away from home.

Unfortunately, Mi Home app does not allow to set up the smoke level when the alarm starts. And sometimes some other devices can be more convenient. For example, if you have this Air Purifier, you can set smoke level (or evan few levels), when Smart home start to do something (e.g. send alarm notification to the smartphone). And with this Air Purifier you don't need gateway, because it works via WiFi and uses Xiaomi Cloud servers.

On another hand, Air Purifier is much more expensive than a Smoke Detector, and has a huge size, which may not fit to your kitchen. And, Air Purifier will not turn on sound alarm unlike Smoke Detector. Additionally, Air Purifier uses external power supply, and will not work without electricity, while the Smoke Detector at least will warn you using the loud sound.

And remember, shuch smoke detectors are only smoke detectors. If you have a gas stove, it make sense to buy additionally Natural Gas Detector.