Marketed to builders, electrical contractors serving single family, multifamily, hotel/motel, RV and manufactured homes channels. The contractor-friendly product and packaging design sets the professional standard. Working smoke alarms cut the risk of dying in a home fire by 50% and that is important because a home structure fire was reported every 86 seconds. Whereas carbon monoxide (CO) is the leading cause of accidental poisoning deaths in America, yet many people do not know they are suffering from CO poisoning until it is too late. Symptoms of carbon monoxide poisoning are like the flu and you might not even know you"re in danger. The SC9120B hardwire alarm comes with 2-in-1 protection to detect CO you can"t see, smell or taste in the air, as well as first signs of a potential fire. This alarm works exceptionally well by using ionization sensor technology to detect fast flaming fires that spread quickly. Sources of these fires include cooktop grease or wastebasket fires. It also includes battery backup for power outages and features a Test/Silence button to check if the alarm is functioning properly as well as silence unwanted or nuisance alarms. This BRK SC9120B Hardwire Smoke and Carbon Monoxide Alarm is an essential product in protecting those who matter most. 9-Volt alkaline battery backup. Latching alarm indicator - remembers which unit initiated an alarm. 2 silence features can silence the low-battery chirp for up to 8-hours or temporarily silence an unwanted nuisance alarm. End of life signal provides audible notification alarms needs to be replaced. Battery door lock and mounting bracket lock for tamper resistance. Low-battery warning chirp and missing battery tab alert you when unit requires a new power source. Quick plug-in power connector for easy installation. Latching alarm indicator remembers which unit initiated an alarm. America's most trusted brand in home safety.