Guide your loved ones safely out of harm’s way with this First Alert Escape Light smoke and fire alarm. Onboard illumination shows the path out if the worst happens, and an ionization sensor picks up the earliest signs of flames. The easy-access door on this First Alert Escape Light smoke and fire alarm makes maintenance easy. Ionization smoke sensor Provides optimal smoke detection from flaming fires. Bright escape light Activates with alarm to illuminate a path to safety. Easy-access battery door There is no need to remove the alarm from the ceiling to change the battery. Mute button Mutes unnecessary alarms immediately.You can also test your alarm function with the same button. Battery operation Eliminates wires. One 9V battery is included.