With the Hombli Smart Bluetooth Contact Sensor, you will receive a push notification on your smartphone as soon as a door or window is opened. The sensor can also be used as a trigger for automations. The Smart Bluetooth Contact Sensor utilizes energy-saving Bluetooth technology and requires a Hombli Smart Bridge (sold separately). This way, you are always informed, whether you are at home on the couch, in the office, or even on vacation. The sensor features a compact and discreet design that blends seamlessly into any interior. It is ideal for doors and windows throughout the house. The Smart Bluetooth Contact Sensor can also be used as a trigger for automations, so for example, your smart lighting can be automatically turned on as soon as a door is opened. Or you can be notified if a window is still open when it starts to rain. The sensor requires a battery and achieves a lifespan of about one year with average use. With the included 3M adhesive tape, the two parts of the sensor can be easily attached to doors and windows as well as their respective frames. Since the sensor uses a Bluetooth connection, you will also need a Hombli Smart Bridge (sold separately).