Do you have no idea if burglars are breaking into your house while you're away? Have you ever imagined that the lights in your apartment turn on immediately when you open the door? Or would you like the lights in your bedroom to automatically turn off as soon as you enter the living room? With the Sonoff DW2-Wi-Fi wireless door/window sensor, any of your ideas can become a reality. The DW2-Wi-Fi consists of two parts: the transmitter is mounted on the door or window, and the magnetic switch is attached to the frame. It can help you secure your door or window, so you know your home is safe, no matter where you are. The sensor triggers an alarm on your smartphone to alert you of an intruder when the door or window is opened. Connect the Sonoff wireless IP camera, and you can see on the sensor page of the app who the intruder is. Whenever your door or window is opened or closed, you can check the opening and closing status in real-time on the eWeLink app. The real-time battery level display and low battery reminder ensure that you know exactly how long the sensor will last and when you need to replace the batteries. Thanks to the easy installation by peeling and sticking, it can be easily mounted in door frames and window sills.