---
product_id: 75629081
title: "FIRST ALERT BRK SC9120B-3 Hardwired Smoke and Carbon Monoxide (CO) Detector with Battery Backup, White, Pack of 3"
brand: "first alert"
price: "¥46522"
currency: JPY
in_stock: true
url: https://www.desertcart.jp/products/75629081-first-alert-brk-sc9120b-3-hardwired-smoke-and-carbon-monoxide
store_origin: JP
region: Japan
---

# Battery Backup Interconnectivity 85dB Siren FIRST ALERT BRK SC9120B-3 Hardwired Smoke and Carbon Monoxide (CO) Detector with Battery Backup, White, Pack of 3

**Brand:** first alert
**Price:** ¥46522
**Availability:** ✅ In Stock

## Summary

> 🔒 Safety First, Always Connected!

## Quick Answers

- **What is this?** FIRST ALERT BRK SC9120B-3 Hardwired Smoke and Carbon Monoxide (CO) Detector with Battery Backup, White, Pack of 3 by first alert
- **How much does it cost?** ¥46522 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.jp](https://www.desertcart.jp/products/75629081-first-alert-brk-sc9120b-3-hardwired-smoke-and-carbon-monoxide)

## Best For

- first alert enthusiasts

## Why This Product

- Trusted first alert brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Loud and Clear!:** 85-decibel siren ensures you won't miss a warning.
- • **Connect and Conquer!:** Easily interconnects with other First Alert devices.
- • **Stay Alert, Stay Safe!:** Hardwired with battery backup for uninterrupted protection.
- • **Double Detection Power!:** Equipped with advanced electrochemical and ionization sensors.
- • **Effortless Installation!:** User-friendly design with tamper-resistant features.

## Overview

The FIRST ALERT BRK SC9120B-3 is a hardwired smoke and carbon monoxide detector that comes in a convenient 3-pack. It features advanced sensing technology, a loud 85-decibel alarm, and a reliable battery backup, ensuring your home remains protected even during power outages. With easy installation and interconnectivity with other alarms, this product is designed for maximum safety and peace of mind.

## Description

FIRST ALERT BRK SC9120B-3 Hardwired Smoke and Carbon Monoxide (CO) Detector with Battery Backup, White, Pack of 3

## Features

- Keep your family safe with this 3-pack of hardwired smoke and carbon monoxide alarm; The battery backup means constant monitoring, even if there's a power failure
- Features an electrochemical carbon monoxide sensing technology as well as an ionization sensor that detects the fine particles of a fast-burning fire
- Indicator lights on the face of the unit display the presence of smoke or carbon monoxide, while an 85-decibel siren provides a clear, loud warning upon detection
- Can connect to other compatible BRK or First Alert detectors, to ensure all alarms will sound when threat is detected
- Simple to use, with a single test/silence button, and side-load battery compartment; Tamper-resistant locking brackets and universal mounting brackets make installation easy. Dust cover

## Technical Specifications

| Specification | Value |
|---------------|-------|
| Brand | FIRST ALERT |
| Style | Hardwired |
| Power Source | Battery Powered,Hardwired |
| Color | White |
| Product Dimensions | 1.9"D x 5.6"W x 5.6"H |
| Item Weight | 11.2 ounces |
| Alarm | Audible |
| Sensor Type | electrochemical,ionization |
| Manufacturer | First Alert |
| Part Number | SC9120BFF-3 |
| Country of Origin | Mexico |
| Item model number | SC9120B-3 |
| Batteries | 2 AA batteries required. (included) |
| Is Discontinued By Manufacturer | No |
| Size | 3-Pack |
| Pattern | Detector |
| Item Package Quantity | 1 |
| Included Components | First Alert BRK SC-9120B Hardwired Combination Smoke and Carbon Monoxide Alarms with Battery Backup (3), Mounting brackets (3), 9-volt battery (3) |
| Batteries Included? | Yes |
| Batteries Required? | Yes |
| Battery Cell Type | Alkaline |

## Images

![FIRST ALERT BRK SC9120B-3 Hardwired Smoke and Carbon Monoxide (CO) Detector with Battery Backup, White, Pack of 3 - Image 1](https://m.media-amazon.com/images/I/715UhOnphWL.jpg)

## Available Options

This product comes in different **Pattern Name, Size** options.

## Questions & Answers

**Q: Why does this model contain the radioactive part? I am sure you are going to tell me that it is a trace amount and that it has all approvals...**
A: The "radioactive part" is how it works.  Don't like it?  Don't buy it.  Simple.

As for false alarms, this unit with its "radioactive part" is actually much more likely to give false alarms that condition people to ignore them.  It is also much less sensitive to the smoldering, smoke-producing fires that are more common in homes.  That's why ionization detectors are no longer recommended in residential settings.  Experts now recommend only photoelectric devices in homes, so if you have these, you should replace all of them with the SC7010B.

**Q: Because its a combo alarm where is the best place to install it since smoke rises and carbon monoxide doesn't?**
A: According to the National Fire Protection Association: Choose smoke alarms that have the label of a recognized testing laboratory.Install smoke alarms inside each bedroom, outside each sleeping area and on every level of the home, including the basement.On levels without bedrooms, install alarms in the living room (or den or family room) or near the stairway to the upper level, or in both locations.Smoke alarms installed in the basement should be installed on the ceiling at the bottom of the stairs leading to the next level.Smoke alarms should be installed at least 10 feet (3 meters) from a cooking appliance to minimize false alarms when cooking.Mount smoke alarms high on walls or ceilings (remember, smoke rises). Wall-mounted alarms should be installed not more than 12 inches away from the ceiling (to the top of the alarm). If you have ceilings that are pitched, install the alarm within 3 feet of the peak but not within the apex of the peak (four inches down from the peak).

**Q: If the alarm goes off, how can you tell whether it's due to CO or fire if there is no voice alert?**
A: I'm sure we'll all remember the number of beeps for each type of emergency, in an actual emergency, when we've been woken up in the middle of the night.
I'll pay the extra $10 per detector and get the voice alert.  I humbly suggest you do the same.

**Q: What is the manufacture date on these items?**
A: Your warranty starts at the date of purchase.  Keep your receipt.  Your 5 year shelf life starts the day you power it up.  The expiration date is hard coded into the software and only starts the day you plug it in..... This is from BRK WEBSITE

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*Product available on Desertcart Japan*
*Store origin: JP*
*Last updated: 2026-02-20*