Protect Smoke & CO Alarm Mains V2Stay protected and sleep soundly with the Nest Protect Smoke & CO Alarm Mains V2, a smart safety device designed to detect both fast burning and smoldering fires, as well as carbon monoxide. Offering advanced features like Split Spectrum Sensor technology, this reliable alarm speaks up when theres an issue and can be silenced directly from your phone when you're at home. If you're away, it sends instant alerts to your phone so you can take action