Conclusion:

With this sensor you can measure the lux (how much light) in a room. It is super compact with its 40x40x12 so you can hang it inconspicuously. It is finished in white plastic and has a transparent cap.

On the side is a button to add it to the controller.

This sensor is unique because there are few Zigbee sensors that only measure the lux value. You can use it ideally to determine whether the lights in your house are allowed to turn on during the day.

It is powered by a CR-2450 battery and retails for around 8.00. This of course makes it very competitively priced.

It is nice to report that the sensor is magnetic so you can stick it on all metal surfaces. A double-sided sticker is also supplied with it.