GUARD is a Bluetooth Mesh and WiFi enabled battery-operated smart door/window sensor that detects and notify you when a door or window is opened or closed, providing the user with a trigger for automating your home. GUARD is also interconnected and can communicate with NEUsmart smart lights (by turning the lights ON or OFF) and PROTECT smart alarm/siren sensor (if an intruder had activated the motion/sound sensor) when used together to create a safe environment for the user.