It's the smoke alarm other alarms look up to. The Nest Protect has an industrial-grade smoke sensor, tests itself automatically and lasts up to a decade. It’s also the first home alarm you can hush from your phone without any extra hardware required. And, it tells you what’s wrong and where. ### In the box * Nest Protect * Backplate * Four screws * Six long-life AA batteries (Battery model) * Three long-life backup AA batteries (Wired model) * 120V AC connector (Wired model) * Three