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Designed to help promote household safety, the First Alert 9120B Hardwired Smoke Alarm with Battery Backup can provide a vital early warning of fire. This hardwired smoke detector uses an ionization smoke sensor to reliably detect smoke from hot, fast-flaming fires.
Ionization Sensor Reliably Detects Flaming Fires
The First Alert 9120B Hardwired Smoke Alarm with Battery Backup comes equipped with an ultra-reliable ionization sensor to provide the earliest possible warning of a fast-flaming fire. The sensor is optimized to detect flaming fires, such as those caused by paper, kitchen grease, and other fast-combusting materials.
Gasket-less for Easy Installation
To facilitate hassle-free installation, this smoke alarm features a streamlined mounting system with a gasket-less base. The mounting bracket keeps the alarm secure over a wide rotation range while maintaining perfect alignment. The alarm also comes with a dust cover to keep the unit clean during construction. AC-powered smoke alarms must be installed in accordance with all local electrical codes.
Battery Backup for Detection During a Power Outage
This smoke alarm is designed for hardwired installation, but it also features a battery backup that helps ensure continued functionality in the event of a power outage. The unit comes with a 9-volt battery and features a pivoting, easy-to-access battery drawer that allows you to replace the battery without dismounting the alarm.
Works in Tandem with Other First Alert Alarms
In addition to functioning independently, this smoke alarm can also integrate with up to 12 other First Alert or BRK hardwired alarms for coverage of larger spaces. It also integrates with up to six other compatible devices, such as bells, horns, and repeaters. If one alarm in the series is triggered, they will all sound. The alarm features a latching indicator to identify which unit triggered the alarm, alerting you to the area of danger.
First Alert Smoke Alarm 9120B
Recommended replacement for the following obsolete models:
First Alert SA4120B
First Alert SA4121B
First Alert SA4919B
Average Rating Based on 166 reviews: (5)
Professional Company - 01/22/2019
Reviewer: Jerry Schlebach
Professional Customer Service I replaced 5 smoke alarms 9120B after 12 years. Thank You for your help! Just unplugged old ones and plugged in NEW ones now I can sleep.
Easy replacement - 01/21/2019
Reviewer: Garth Lien
Easy to replace the pigtail for the new smoke detectors. All tested good. Easy directions. The mounting plate is larger than the original. Makes for a nicer visual fit. Mounting plate has many different screw pattern options. Battery access is very convenient. Would order them again. I ordered from the First Alert store fast shipping.
It connects with the group - 01/21/2019
Reviewer: Shawn Long
We had 1 go bad and ordered this one which is the newer model of the rest of the house. All I had to do was install this with the base it came with and connected it up. All other detectors love it so I'm guessing it works. Lights show good.
Smoke Detector - 01/17/2019
Reviewer: Brian Bishop
Great deal on 5 smoke detectors. Very easy to install. Would buy again.
Reviewer: John Klus
Unit replaced existing ones with direct plug in replacement. Quick and easy installation.
First Alert Review - 01/16/2019
Reviewer: Gloria Markham
Perfect replacement. Thank you.
Replacement - 01/15/2019
Reviewer: Ashley Donnelly
Bought to replace and old smoke alarm and it fit perfectly. It was also delivered as promised.
Smoke Detector - 01/11/2019
Reviewer: Robert Jarosik
Until I have a fire, I really can't review this product because I don't smoke. Your service was great.
Easy Replacement - 01/10/2019
Reviewer: Michelle Howard
Easy plug in to replace old unit with new one. The old units were the same model and lasted for 10 years.
Smoke - 01/10/2019
Reviewer: YILI Pan
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