Alarm Firex Heat Hard Wired Rechargeable Battery BackupThe Firex Hard Wired Heat Alarm with Rechargeable Battery Backup is a reliable heat detection unit ideal for areas where smoke alarms are prone to false activation, such as laundry rooms, lofts, and garages. This mains powered alarm features a built in tamper proof lithium backup battery, ensuring continued protection during power outages. With the ability to interlink with up to 23 Firex alarms, it provides whole home coverage, and its alarm memory