【Not alone】The sensor cannot be used alone and must be used in conjunction with the alarm host. "Add a device" in the app to configure. With the help of a webcam, you can keep track of your home situation at all times when something unusual happens. 【Easy to install】Wall-mounted, easy to install and configure the sensor. No professional installation required, you can do it yourself. This product has reserved screw holes, and you can also install it with screws. 【Has many uses】The sensor's signal range is large enough to reach every corner of most homes. This product is widely used in homes, factories, schools, grocery store garages, etc.