The Energizer Connect Smart Wireless WiFi Door and Window Sensor with Instant Notifications is a fantastic security measure. Receive alerts whenever your doors or windows are opened. You can also set your sensor to only notify you between certain hours such as through the night or while you are away at work. You can automate your sensors to activate other Energizer Connect Smart products in your home such as activating a light bulb when your front door is opened. No hard-wiring or cables necessary, simply apply the sensor to your door or window and sync with your smartphone!