FIRST ALERT BRK SC9120B-3 Hardwired Smoke and Carbon Monoxide (CO) Detector with Battery Backup, White, Pack of 3

• Keep your family safe with this 3-pack of hardwired smoke and carbon monoxide alarm; The battery backup means constant monitoring, even if there's a power failure
• Features an electrochemical carbon monoxide sensing technology as well as an ionization sensor that detects the fine particles of a fast-burning fire
• Indicator lights on the face of the unit display the presence of smoke or carbon monoxide, while an 85-decibel siren provides a clear, loud warning upon detection
• Can connect to other compatible BRK or First Alert detectors, to ensure all alarms will sound when threat is detected
• Simple to use, with a single test/silence button, and side-load battery compartment; Tamper-resistant locking brackets and universal mounting brackets make installation easy. Dust cover