Hardwired smoke detectors are wired directly into your homes electrical system. Detector includes battery backup and mute button. Battery backup ensures alarm works even during power outages. Mute feature silences nuisance alarms from cooking smoke or shower steam and single button tests alarm functions. Easy access drawer for battery: no need to take down alarm from ceiling to change battery. Interconnects with up to 12 other First Alert or BRK hardwired alarms. 10-year limited warranty. Meets UL smoke detector standards.