The First Alert CO400 Carbon Monoxide Alarm utilizes an electrochemical carbon monoxide sensor that lasts for up to five years to detect carbon monoxide. This carbon monoxide detector is battery powered, making it portable and easy to use anywhere, even in the event of a power outage. When carbon monoxide levels become elevated, a loud 85-decibel alarm alerts you to the threat.

The Most Accurate CO Sensor Available: The First Alert Carbon Monoxide Alarm uses an advanced electrochemical CO sensor to detect elevated carbon monoxide levels. When CO is detected, the carbon monoxide detector sounds an alarm to warn you of the threat.

Comprehensive Warning Features: When carbon monoxide levels rise, the carbon monoxide detector sounds an 85-decibel siren that is designed to wake even the soundest of sleepers. A low-battery light and alarm alert you when battery power is running low, and an end-of-life timer lets you know when the device should be replaced. Each CO detector lasts approximately five years.

Simple and Easy to Use: The First Alert Carbon Monoxide Alarm is easy to set up. Simply insert the battery, and the CO detector will start to monitor your space for carbon monoxide. There are no complicated displays or settings to navigate. A single button silences the alarm and tests the CO detector. A pull-down action chart instructs you of what to do if the CO alarm goes off.

Where To Place Carbon Monoxide Alarms: One on every level of the home and one in each sleeping area.