First Alert BRK 7020B Hardwire Photoelectric Sensor Smoke Alarm with Battery Backup and Escape Light

The 7020B AC-powered smoke alarm includes these features:

• Photoelectric sensor which is more effective at detecting smoldering fires which smolder for hours before bursting into flame.
• 120-volt VAC inter-connectable (with maximum 18 compatible devices). The alarm can be interconnected with up to 12 other compatible smoke alarms and six compatible devices like bells, horns, repeaters and door closers. If one unit triggers an alarm, all smoke alarms in the series will sound. Power indicators show which unit in the series initiated the alarm.
• Escape light to help illuminate a path to safety.
• Automatically performs internal test of functionality.
• Quick connect pig tails for easy installation.
• 9-volt battery backup for peace of mind during power malfunction.
• Universal mounting bracket with screw slots.
• Optipath 360 technology allows 360-degree access to the layer of air on the ceiling or wall that carries the fire signatures (smoke, combustion particles and volatile components).
• Single test/silence button which both silences a non-threatening alarm or low battery warning and allows you to test the unit's functionality.
• Low battery indication to alert you to change the backup battery.
• 10-year limited warranty.

What's in the Box
One smoke alarm, one 9-volt battery, and user's manual.