First Alert CO605 Carbon Monoxide Plug-In Alarm with Battery Backup is designed to provide reliable protection against dangerous carbon monoxide levels in your home. Equipped with an advanced electrochemical CO sensor, this alarm efficiently detects carbon monoxide and alerts you promptly to ensure your safety. The alarm conveniently plugs into any standard electrical outlet, making installation quick and hassle-. It also includes a battery backup that keeps the alarm operational during power outages, giving you continuous peace of mind. For ease of use, the alarm features a test button that allows you to quickly verify its functionality. Additionally, it has an end-of-life warning chirp to notify you when it’s time to replace the unit. To maintain optimal performance, it is to change the batteries at least twice a year. Model Number: 1039734