BRK has been the top choice of contractors in the commercial market for over 50 years. 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's important because a home structure fire was reported every 86 seconds. The faster you know about a fire, the faster you can start moving your family outside. The 9120B hardwire 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. Plus, this alarm allows easy alignment with the perfect mount feature and comes with battery backup. This BRK 9120B Hardwire Smoke Alarm is an essential product in protecting those who matter most. Smart technology - helps reduce the number of nuisance alarms. Latching alarm indicator - remembers which unit initiated an alarm. 9-Volt battery backup. Single test/silence button.