The Kidde Smart Carbon Monoxide Detector & Indoor Air Quality Monitor uses electrochemical sensor technology to detect poisonous CO gas in your home and alert you by sounding an 85-decibel alarm with a voice alert announcing "Warning! Carbon Monoxide!". The Kidde carbon monoxide alarm plugs into a standard, 120V AC power outlet and 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 have the benefit of never having 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 CO presence, high humidity levels that can lead to mold, unexpected high or low temperatures, or Total Volatile Organic Compounds (TVOCs). Setup is easy: simply download the Kidde app, scan the QR code at the back of the CO alarm, & plug the unit into your wall outlet. 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. A digital display screen on the plug-in carbon monoxide alarm provides real-time information on the status of indoor air quality and carbon monoxide levels. Two buttons are provided for easy accessibility: the Test-Hush temporarily silences nuisance alarms, tests if the unit is operating properly, and silences a low battery or end-of-life chirp (up to 24 hours at a time for a maximum of 7 days), while the Peak Level Memory Button records the highest CO level reached since the button was last pressed. Install a smoke detector on each level of your home and inside and outside each bedroom. UL Certified with a 10-year limited warranty (not a battery performance claim).