Nest's Protect Smoke/CO Detector
Nest’s Protect smoke and carbon monoxide detector has an industrial-grade smoke sensor, tests itself automatically and lasts up to a decade. It has a human voice and, because all a home's detectors are connected, an alarm in an upstairs bedroom will announce smoke downstairs. Users receive warnings, alarms and low-battery chirps on their phone and can silence them from there. It also has a pathlight that lights up as a user walks underneath it and Steam Check, a system that uses a humidity sensor to prevent false alarms.