Hardwired smoke detectors are alarms wired directly into your homes electrical system and include battery backup and mute button. Hardwired smoke detectors with battery backup ensure that alarms work even during power outages. Includes adapter plugs to easily replace other non-First Alert branded detectors without rewiring. Mute feature silences nuisance alarms and single button tests alarm functions. Easy access to battery drawer: no need to remove alarm to change battery. Can integrate with up to 12 other First Alert or BRK hard wired alarms. 10-year limited warranty. Meets UL standards.