Combining premium smoke detection with a sleek, compact design, the First Alert Micro Photoelectric Smoke Alarm with 10-Year Battery delivers the same advanced protection as a traditional alarm while taking up only a fraction of the space. This smoke detector uses an ultra-reliable photoelectric sensor to detect smoke from smoldering fires while keeping false alarms to a minimum. A built-in 10-year lithium-ion battery provides continuous power, with no need to ever worry about changing batteries during the lifetime of the alarm. Much smaller than an ordinary smoke detector, this unit is manufactured using 52 percent less resin and 76 percent less plastic than a standard alarm. The SmartClip mounting system allows you to effortlessly install the detector on a wall or ceiling. A loud 85-decibel siren sounds if smoke is detected, and a convenient test/silence button lets you easily check alarm function and mute false alarms. What's Included: Mounting bracket with hardware and User Manual10-year sealed photoelectric smoke alarm.10-year limited warrantyPowered by sealed, 10-year lithium batteries to provide continuous protection for 10 years without battery replacement.10-year battery eliminates annoying low battery chirps in the middle of the nightPhotoelectric smoke sensing technology for less nuisance alarms85-decibel alarm is designed to be heard easily.Meets UL217 standards and complies with legislative requirements for 10-year battery operated smoke alarmsSmartClip mounting system for effortless installation on a wall or ceiling.Single button test/silence to ensure your alarm is working properlyEnd of life signal alerts you when alarm needs to be replaced