https://www.cnet.com/news/ces-2019-an-arlo-home-security-system-is-here-at-last/ > Arlo claims its Multi-Sensor is an "all-in-one" device that detects motion, doors and windows opening and closing, smoke and carbon monoxide alarms, changes in temperature and water leaks. In theory, if it works, you wouldn't need individual sensors on every door and window. > The Arlo Siren can be used outside and runs on batteries. Use the Arlo Remote to arm and disarm the system and more.