Ensure you are alerted to dangerous carbon monoxide leaks with the First Alert CO5120PDBN Hardwired Carbon Monoxide Alarm. This carbon monoxide detector uses an electrochemical carbon monoxide sensor, and it comes equipped with a microprocessor that helps minimize false alarms. It also features a backlit digital display that shows current and peak levels. A plug-in power connector makes installation quick and easy, while a tamper-resistant mounting bracket lock keep the alarm secure. Featuring a 9-volt battery backup, this unit is designed to offer seamless detection, even in the event of a power outage. An 85-decibel horn sounds if carbon monoxide levels are too high, and a warning chirp notifies you when batteries need to be replaced. This carbon monoxide alarm can integrate with up to 12 other First Alert or BRK hardwired alarms and up to six other compatible devices--such as bells, horns, and repeaters--making it ideal for comprehensive coverage of large households or facilities. A latching alarm indicator automatically identifies which unit in the series triggered the alarm. And thanks to unit's convenient test/silence button, it is easy to check whether the alarm is functioning properly and mute false alarms.