First Alert 10-Year 2-Pack Battery-Operated-Volt Photoelectric Sensor Smoke Detector

Combining premium smoke detection with a sleek, compact design, the First Alert P1010 atom photoelectric smoke alarm with 10-year battery uses an ultra-reliable photoelectric sensor to detect smoke from smoldering fires while keeping false alarms to a minimum. A built-in 10-year 3V lithium-ion battery provides continuous power with no need to ever worry about changing batteries for the lifetime of the alarm. It's manufactured using 52% less resin and 76% less plastic than a standard alarm. The easy mounting system allows you to effortlessly install the detector on a wall or ceiling. A loud 85-decibel siren sounds if smoke is detected, a convenient test/silence button lets you easily check alarm function and mute false alarms, and an end-of-life signal lets you know when it's time to replace the unit.