First Alert SA350B, Battery Ionization Sensor Smoke Alarm 3 Pack

First Alert SA350B, Battery Ionization Sensor Smoke Alarm 3 Pack Smoke detector with built-in 10-year 3-volt lithium power cell for long-lasting performance Ionization sensor for efficient smoke detection, ensuring quick response to smoke Tamperproof design prevents batteries from being removed, enhancing safety Easy mounting bracket included for straightforward installation Alarm end-of-life indicator alerts you when it's time to replace the unit