Model 20SDR AA battery powered smoke alarm with LED warning lights. Features enhanced sensing technology which reduces false alarms often caused by cooking. Provides fast alerts - upon sensing smoke or fire, an 85-decibel alarm sounds and a red LED will illuminate. Includes 3 LED lights that indicate alarm status. Green means normal operation, amber means there is an operating error, and red means that smoke detected. No wiring needed, install with the included twist-and-click mounting bracket. Self-testing design checks that internal components of the alarm are always operating as expected. Self-testing is not a substitute for a weekly manual push test of the alarm. The test & hush button makes it easy to test the smoke detector and silence false alarms, should they occur. A low battery chirp alerts you when batteries need replacing. The alarm will sound as a reminder when it is time to replace the alarm after 10 years of use after its original power-up date. Meets requirements of the following authorities - Underwriters Laboratories (UL), Federal Housing Authority (FHA), Housing and Urban Development (HUD), National Fire Protection Association (NFPA). Comprehensively tested & certified to meet requirements of UL 217 8th & 9th Edition, and FCC standards. 10-year limited warranty.