Its time to expect more from your smoke alarm. The new Nest Protect has been redesigned from the inside out. It has an industrial-grade smoke sensor tests itself automatically & lasts up to a decade. It's also the first home alarm you can silence from your phone without any extra hardware required. & just like the original Nest Protect it tells you whats wrong & can even alert your phone. Meet the all-new Nest Protect. The smoke alarm other alarms look up to. This alarm is battery powered.