Kidde AC Hardwired Interconnect Smoke Alarm with Safety Light I12080 Ideal for hallways with emergency safety light to guide you to safety. Safety Light illuminates the path to safety Alarm memory flashes red LED indicating which unit was the initiating alarm in interconnected system Interconnectable with up to 24 devices (of which 18 can be initiating) including smoke, CO and heat alarms. See users guide for complete instructions Fewer Callbacks - One button design for easy operation and less confusion. Operates Hush and alarm test. Battery run down protection will shut down alarm memory when AC power is not present, reducing low battery chirp. Dust cover protects sensor from contaminates during construction reducing nuisance alarms Easy Installation - Front battery pull tab allows battery activationwithout removing alarm from mounting bracket. Large mounting base makes mounting easier, protects surface paint from dirt and covers imperfections. Pre-stripped wiring harness with easy off cap does not require stripper tool. Tinned strands increase conductivity and wire nut grip