Have no idea whether burglars break into your home in your absence? This wireless door/window sensor can help secure your door or window to let you know whether your home is safe wherever you are. The sensor will trigger an alarm to your smartphone to remind you of an intruder when the door or window is opened. Connect it to your smartphone via WiFi and receive real-time opening and closing status on the app. It also has a low-battery reminder to ensure you get clear know how long the sensor can run and when you need to replace batteries. With simple peel and stick installation, it is easy to fit in door frames and window sills.