The Kidde 20SDRGo to product viewer dialog for this item. is a pack of three modern 5-inch residential smoke detectors designed to elevate home fire safety. Powered by two replaceable AA alkaline batteries, each unit ensures continuous photoelectric smoke monitoring even during power outages. It features advanced sensing technology that drastically minimizes false alarms caused by standard cooking steam. When smoke or fire is detected, a loud 85-decibel siren sounds in tandem with a flashing red LED light to provide an early warning. The unit includes a convenient test-hush button to easily silence nuisance alerts and check system operations. A low-battery chirp indicates when replacement batteries are required, and an end-of-life alarm signals when the 10-year operational lifecycle concludes. Built with an easy twist-and-click mounting bracket, this wire-free system offers swift ceiling installation without complex wiring