The Kidde Wireless AC Powered Smoke Alarm makes it easy to expand the coverage of a current interconnected system. Simply replace oneinterconnected smoke alarm with the Kidde Wireless AC powered alarm. Kidde Wireless Battery Powered Smoke Alarms can be installed in additional rooms that need extra protection. This AC powered alarm bridges a home's current interconnected system to the newly installed alarms, so that when onealarm is triggered, all alarms will sound. Experts recommend interconnected alarms, because when onesounds, they all sound, providing an early warning against fire by dramatically increasing your ability to hear an alarm anywhere in your home, regardless of where the fire starts. Newer homes are required by code to have interconnected alarms. Wireless technology now enables any home to have an interconnected system.