FIRST ALERT HD6135FB Heat Alarm with Battery Backup, 120 V, Thermistor Sensor, 50 ft Detection, Alarm: Audible [SKU: ORG4744744]

9 V battery backup, Microprocessor controlled for fewer nuisance alarms, The test/silence button both silences a non-threatening alarm or low battery warning and allows you to test the unit's functionality, Latching alarm indicator which automatically identifies which unit initiated the alarm, Alarm can be interconnected with up to 12 other compatible smoke alarms and six compatible devices like bells, horns, repeaters and door closers. [QTY/UOM: 1EA / 1EA]