Kidde 1279-9999 Wireless AC Powered Smoke Alarm, 3 pc: * When 1 alarm sounds, they all do * Ability to interconnect without wires * Install in minutes, almost anywhere in the home * Less cost and less hassle than re-wiring * Makes it easy to expand the coverage of a current interconnected system * Simply replace 1 interconnected smoke alarm with the Kidde Wireless AC Powered Smoke Alarm * 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