First Alert carbon monoxide alarm. Set of 2

The First Alert CO605 Plug-In Carbon Monoxide Alarm with Battery Backup utilizes an electrochemical carbon monoxide sensor to accurately and effectively warn you of elevated CO levels. The plug-in design and included battery backup mean your space can be continuously monitored for dangerous carbon monoxide gas, even during power outages. Simply plug the alarm into a 120-volt outlet, and the personal carbon monoxide detector is ready to go. When CO levels rise above a safe threshold, a loud 85-decibel alarm alerts you to the threat. Designed for simple use, the CO detector has just 1 button that silences or tests the unit, as well as an end-of-life timer that lets you know when it is time to replace the device. Simple and Easy to Use: The carbon monoxide monitor is easy to set up: simply plug it into a standard electrical outlet to monitor your space for carbon monoxide. There are no complicated displays or settings.