The Kidde Smart Smoke Detector & Indoor Air Quality Monitor, WiFi, Alexa Compatible Device, Hardwired with Battery Backup, Voice & App Alerts Value Pack, models P4010ACSAQ-WF, is an industry-first, combination smoke alarm & indoor air quality monitor. The Kidde smart hardwired smoke alarm uses photoelectric sensor technology to detect visible fire particles, associated with smoldering fires, and alerts you by sounding an 85-decibel alarm with a voice alert announcing "Fire! Fire!". The Kidde smoke alarm connects to your home's wiring using standard 120V AC power voltage & provides battery backup in the event of a power failure. The lithium battery backup lasts the full 10-year life of the alarm, so you'll never have to replace a battery. Up-to-date, real-time notifications are provided through the Kidde app, so your family & friends - even the pet sitter - can monitor your home's air quality & receive alerts to smoke presence, high humidity levels that can lead to mold, or Total Volatile Organic Compounds (TVOCs). Setup is easy: simply download the Kidde app, & scan the QR code at the back of the smoke alarm. You can also use voice commands to check the connection & status of carbon monoxide or air quality by pairing it with your Amazon Alexa, Google Home, and select iPhone & Android smart devices. The LED ring-light indicator alerts you to the unit's operational status: red = a smoke or fire hazard, amber = operating error, and green = normal operation. The Test-Hush button silences temporary nuisance alarms, tests if the unit is operating properly, & silences a low battery or end-of-life chirp (up to 24 hours at a time for a maximum of 7 days). Capable of hardwired interconnection to other select Kidde alarms for whole-home activation – when one alarm sounds, they all do**. UL Certified with a 10-year limited warranty (not a battery performance claim). **Alarms only connect with select Kidde alarms that have hardwired AC interconnect capability (see User Guide).