SONOFF Wireless Door/Window Sensor can be placed on your door or window to let you know with an alert notification whether your door or window is open or closed, adding an extra layer of security to your home. The opening and closing status of the door/window is synchronized to your mobile phone, so you don't have to wonder whether the door/window is off or not. SONOFF ZigBee Bridge is required . The sensor offers you the possibility to create a scene link between ZigBee and Wi-Fi devices. This sensor is able to help you create a smart home. Working in harmony with the SONOFF ZigBee Bridge, you can stage a scene so your hallway is lit as soon as the door is opened. Simple installation for easier set-up, installation 3M tape (included) saves you a lot of time. Its application can also extend to large areas such as drawers, garage doors, blinds, etc. Just stick it anywhere two things are connected and it's still safe even if you're not watching it. Share the sensor with your family to give them the ability to control and monitor quickly your house together. 3-month history check. The camera function can be activated on the sensor page in the APP eWeLink, which also allows you to clearly see who enters your house; you can even scare the stranger into leaving your house immediately with the two-way audio feature. Number of sends: 1 pcs