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 lithium battery-operated smoke alarm provides coverage during power outages as well as throughout the life of the alarm 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 a 3-Volt lithium battery (included inside the alarm) providing easy installation, simply mount the bracket onto the ceiling and twist & click the smoke alarm into the bracket No Battery Replacement Needed: the 10-Year lithium battery lasts the life of the alarm - a low battery chirp alerts you when the alarm needs replacement 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 meet requirements of UL 217 9th Edition, FCC, CSFM, and California Prop 65 standards