The Nest Protect Smoke/Carbon Monoxide Alarm looks for both fast and slow-burning fires. It can alert your phone and tell you where the danger is and it lets you hush a false alarm with your phone. You can know what’s going on, from anywhere. When something’s wrong, Nest Protect sends everyone an alert in case no one’s home. Tired of getting woken up at 2 a.m. by your smoke alarm? "Chirp Chirp" Long before it has to chirp, Nest Protect tells you its batteries are running low with a message on your phone. It also detects the colorless and odorless carbon monoxide to keep your family safe in the event of a leak.