First Alert BRK Hardwired Ionization Smoke Alarm

Easy to install hardwired smoke alarms meets new construction requirements. The BRK 9120B smoke sensor is the most accurate sensor available and can use a 9V alkaline battery as a backup. Smoke sensors are important for use in residential and commercial buildings. Interconnectable - Can be interconnected with up to 12 smoke alarms and the remaining six can be a combination of heat alarms, CO alarms and relays 9-volt backup battery (included) for constant monitoring Intelligent Sensing Technology - Reduces the number of non-emergency or "nuisace" alarms Single Button Test/Silence Dust Cover Single button test/silence 10-Year Limited Manufacturer Warranty