Protect your family and your home from house fires with the Kidde I4618 Hardware Smoke Alarm. It s a wired-in device that features ionization-sensing technology to quickly pick up and alert you to fires. The hush-button smoke alarm includes a front-loading battery door and a power-link tab for quick change convenience. It also has the ability to temporarily silence the unit if needed. Additionally the Kidde I4618 Hardwire Smoke Alarm includes a backup 9V battery in case of a power outage and it has a large mounting base to make installation easier. You can also interconnect the unit with other Firex smoke alarms and heat alarms compatible with other contractor preferred Firex products (sold separately).