The Nest Protect detects smoke and carbon monoxide, tests itself regularly, sends intelligent alerts, and connects to your entire smart home.
Aside from a smoke detector, it also includes a humidity sensor, which can cut down on false alarms caused by steam; a motion sensor, which activates the Nest's nightlight when you're up and about after dark; and an ambient light detector, which senses when you've turned out the lights and lets Nest know to flash green -- indicating that it has performed its self-check and everything's in working order.
The Nest Protect comes in both a hardwired and battery-operated version, making compatible with any home.
Not sure which kind you need? Simply unscrew one of your existing detectors from its mount: If it's connected to the wall with wires, your home has a hardwired system. If not, it's battery operated.
Peace of mind, automatically
The Nest Protect regularly checks its battery (or backup battery, if you have the hardwired version). It also performs routine siren checks every month and will send you a mobile notification if either component isn't working properly. This ensures that your alarm's battery or loudspeaker won't fail when you need it.
Perfect addition to a Google Home ecosystem
Although the Protect is great as a standalone unit, it's at its best when paired with other Nest devices.
The family of products is designed to work together in intelligent ways: for instance, if Nest Protect detects an emergency, your Nest Thermostat can be programmed to shut off all heat and forced air systems to prevent the spread of smoke or CO.
The Nest Protect smart smoke and CO detector only works with Google Assistant, so it doesn't work with others like Amazon Alexa or Apple's Siri.