Advanced Sensor Technology: photoelectric sensor technology provides advanced smoke detection in sensing visible fire particles associated with smoldering fires to reliably detect smoke or fire hazards Reduces Nuisance Alarms: sensor technology reduces false alarms often caused by cooking or shower steam Self-Testing Alarms: internal components ensure alarm is always operating as expected. Self-testing is not a substitute for a manual push test of the alarm. Perform a button test once per week to verify proper alarm operation. Peace of Mind: the Kidde battery-operated smoke alarm provides coverage during power outages Early Warning Detection: upon sensing smoke or fire, an 85-decibel alarm sounds & a red LED will illuminate 3 LED Indicators: illuminate based on status of smoke alarm: green = operating properly, amber = fault in operation or error, red = smoke or fire indicated No Wiring Needed: operates on 2-AA alkaline batteries (included) providing easy installation, simply mount the bracket onto the ceiling and twist & click the smoke alarm into the bracket Battery Replacement: a low battery chirp alerts you when batteries need replacing End-of-Life Alarm: alarm sounds as a reminder when it is time to replace the alarm after 10 years of use after its original power-up date Test-Hush button makes it easy to test the smoke detector and silence false alarms, should they occur UL Listed: comprehensively tested to meets requirements of UL 217 9th Edition and FCC standards