The First Alert hardwired smoke alarm is a device designed to detect the presence of smoke in the air and alert you with a loud siren in the event of a fire. It is a small, round device with a white color, and smooth exterior. The front of the device features a red LED light that indicates the presence of smoke, and the back of the device has a tamper-resistant battery compartment.
To use the smoke alarm, simply mount it on the ceiling or wall using the included mounting hardware. Once installed, the device will automatically start detecting smoke and will sound the alarm if it detects a certain level of smoke in the air.
The smoke alarm is equipped with an ionization sensor, which is designed to detect fast-flaming fires. It also has a loud, 85-decibel alarm that can be easily heard throughout most residential or commercial buildings. In addition, the device has a latching alarm indicator that automatically identifies which unit initiated the alarm, even after the conditions that set off the alarm have subsided.
The smoke alarm also includes a 9-volt battery backup that will continue to protect you in the event of a power failure. This ensures that you are always protected, even if the power goes out. The device also has an end-of-life signal that lets you know when it is time to replace the unit.
One of the unique features of the First Alert hardwired smoke alarm is its ability to connect to compatible BRK or First Alert alarms within a single-family residence. When one alarm is triggered, all connected alarms will sound, providing an extra level of protection for you and your family.
Overall, the First Alert hardwired smoke alarm is an essential safety device for any home or business. It is easy to install, affordable, and will alert you to the presence of smoke in the air with a loud siren. It is a reliable and effective way to protect your home or business from fires.

First Alert BRK 9120B Hardwired AC Smoke Detector Alarm w/ Battery Backup:

• 9-volt battery backup in case of power failure
• Ionization sensor detects smoke and fast-flaming fires
• 85-decibel alarm
• One button silences/tests alarm
• The latching alarm indicator shows which unit triggered the alarm
• End-of-life signal lets you know when to replace unit
• Can connect to other BRK or First Alert alarms in single-family home for simultaneous sounding