
Sorry, this item is out of stock
Browse similar items
First Alert SMI100-AC, Hardwire Interconnect Smoke Alarm with Battery Backup, 3-Pack $55.90
$5590current price $55.90First Alert SMI100-AC, Hardwire Interconnect Smoke Alarm with Battery Backup, 3-Pack
224.3 out of 5 Stars. 22 reviewsFirst Alert 1046834, Electric Precision Detection Smoke Alarms $24.84 Was $33.00
$2484current price $24.84, Was $33.00$33.00First Alert 1046834, Electric Precision Detection Smoke Alarms
744.5 out of 5 Stars. 74 reviews10 Year Smoke CO Alarm w Voice $53.95
$5395current price $53.9510 Year Smoke CO Alarm w Voice
183.9 out of 5 Stars. 18 reviewsBRK Hard-Wired w/Battery Back-up Ionization Smoke Detector $19.25 Was $29.00
$1925current price $19.25, Was $29.00$29.00BRK Hard-Wired w/Battery Back-up Ionization Smoke Detector
724.7 out of 5 Stars. 72 reviewsFirst Alert 1046736, Battery Photoelectric Sensor Smoke Alarm 2 Piece $55.99 Was $62.99
$5599current price $55.99, Was $62.99$62.99First Alert 1046736, Battery Photoelectric Sensor Smoke Alarm 2 Piece
234.9 out of 5 Stars. 23 reviewsUniversal Security Instruments Hardwire Smoke & Fire Alarm, with 10-Year Battery Backup $44.97
$4497current price $44.97Universal Security Instruments Hardwire Smoke & Fire Alarm, with 10-Year Battery Backup
Universal Security Instruments Hardwire Smoke & Fire Alarm, with Battery Back-up $27.97
$2797current price $27.97Universal Security Instruments Hardwire Smoke & Fire Alarm, with Battery Back-up
15 out of 5 Stars. 1 reviews10 Year Worry-Free Battery Powered Smoke Detector with Ionization Sensor $26.94
$2694current price $26.9410 Year Worry-Free Battery Powered Smoke Detector with Ionization Sensor
23 out of 5 Stars. 2 reviewsUniversal Security Instruments Battery, Smoke & Fire Alarm $17.97
$1797current price $17.97Universal Security Instruments Battery, Smoke & Fire Alarm
43.8 out of 5 Stars. 4 reviewsUniversal Security Instruments 10-Year Battery, Smoke & Fire Alarm $29.97
$2997current price $29.97Universal Security Instruments 10-Year Battery, Smoke & Fire Alarm
Universal Security Instruments Inc Sensing Plus, Smoke and Fire Alarm, Multi-Criteria Detection, with 10 Year Sealed Battery $27.97
$2797current price $27.97Universal Security Instruments Inc Sensing Plus, Smoke and Fire Alarm, Multi-Criteria Detection, with 10 Year Sealed Battery
534.5 out of 5 Stars. 53 reviews50+ bought since yesterday First Alert SMI100 Battery-Operated Smoke Alarm, 1046827PT $16.99 $28.80/ea
$1699current price $16.99$28.80/eaFirst Alert SMI100 Battery-Operated Smoke Alarm, 1046827PT
644.4 out of 5 Stars. 64 reviewsUniversal Security Instruments Hardwire Smoke, Fire, Carbon Monxide, with Battery Backup, Voice Alert Alarm $64.97
$6497current price $64.97Universal Security Instruments Hardwire Smoke, Fire, Carbon Monxide, with Battery Backup, Voice Alert Alarm
Universal Security Instruments Hardwire Smoke, Fire, Carbon Monxide Alarm, with 10-Year Battery Backup $69.97
$6997current price $69.97Universal Security Instruments Hardwire Smoke, Fire, Carbon Monxide Alarm, with 10-Year Battery Backup
15 out of 5 Stars. 1 reviewsFirst Alert Standard Battery-Operated Smoke Alarm and CO Alarm Value 2 Pack with Models SMI100 and CO400, 1046718PT $34.99 $24.99/ea
$3499current price $34.99$24.99/eaFirst Alert Standard Battery-Operated Smoke Alarm and CO Alarm Value 2 Pack with Models SMI100 and CO400, 1046718PT
64.8 out of 5 Stars. 6 reviewsFirst Alert Dual Sensor Smoke Alarm with 10-Year Sealed Battery, 1 pk $64.99
$6499current price $64.99First Alert Dual Sensor Smoke Alarm with 10-Year Sealed Battery, 1 pk
First Alert SC5 Hardwire Smart 2-in-1 Smoke and CO Alarm with Voice Alerts and Battery Backup $139.99
$13999current price $139.99First Alert SC5 Hardwire Smart 2-in-1 Smoke and CO Alarm with Voice Alerts and Battery Backup


Hero image 0 of First Alert BRK 3120B Hardwired Photoelectric and Ionization Smoke Alarm with Battery Backup, 85 Decibels, 0 of 5
First Alert BRK 3120B Hardwired Photoelectric and Ionization Smoke Alarm with Battery Backup, 85 Decibels
Key item features
- Advanced Detection: Equipped with Opti path 360 technology for 360-degree smoke detection
- Comprehensive Coverage: Place one alarm on each level of your home and in each bedroom for complete protection
- User-Friendly Design: Features a single test/silence button and side-load battery compartment for easy use
- UL Certified: Rigorously tested to meet UL standards for safety and reliability
- Battery Backup: Includes a battery backup to ensure protection during power failures
- Interconnectable: Can be linked with up to 18 compatible devices for synchronized alerts
- Dual Sensors: Features photoelectric and ionization sensors for detecting both smoldering and fast-flaming fires
- Loud Alarm: Emits an 85-decibel alarm designed to be heard by those with age-related hearing loss
Generated by AI
Specs
- Power typeBattery
- Battery life4320 h
- Smoke & carbon monoxide alarm sensor technologyPhotoelectric Sensor
- Featureswith Silence Button
- Batteries inclY
- Smart techN
Current price is USDNow $52.96
You save $10.11
was $63.07$63.07
You save$10.11
Price when purchased online
Out of stock
How do you want your item?
Out of stock
Continue your search on Walmart
About this item
Product details
The First Alert BRK 3120B Hardwired Smoke Alarm includes a battery backup that continues to protect you in the event of a power failure. It’s designed for residential use as well as for institutional locations such as hospitals, hotels, dorms, and multiple-family dwellings. This alarm is interconnectable and can be linked with up to 18 compatible devices (up to 12 smoke alarms and 6 compatible devices like bells, horns, and repeaters) so that when one triggers, all alarms sound. This alarm emits a loud, spread-spectrum 85-decibel alarm designed to be heard by those with age-related hearing loss. The First Alert Dual Sensor Smoke Alarm features photoelectric and ionization sensors for increased detection. The photoelectric sensor detects smoldering fires from objects like cigarettes burning on furniture or in trash cans, while the ionization sensor detects fast-flaming fires like erupting kitchen grease fires or combustibles. One button silences any nuisance alarms, and also tests detector functions, while lights indicate if the alarm detects smoke. The latching alarm indicator automatically identifies which unit initiated the alarm, even after the conditions that set off the alarm have subsided. And an end-of-life signal enhances your safety by letting you know when it's time to replace the unit.
- Equipped with Opti path 360 technology that enhances detection with 360-degree access, and reliably detects smoke
- To ensure complete protection make sure to place one on each level of your home and in each bedroom
- Simple to use, with a single test, silence button and side-load battery compartment; included mounting bracket makes installation easy
- Rigorously tested to meet UL standards
info:
We aim to show you accurate product information. Manufacturers, suppliers and others provide what you see here, and we have not verified it. Â
Specifications
Power type
Battery
Battery life
4320 h
Smoke & carbon monoxide alarm sensor technology
Photoelectric Sensor
Brand
Unbranded
Warranty
Warranty information
All products come with a 90 Day, or longer, manufacturer warranty
Warranty url
Warnings
Warning Text
proposition 65 reasons:WARNING: This product can expose you to chemicals which are known to the State of California to cause cancer or birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov/.
More items to consider
Based on what customers bought
First Alert SC9120B Direct Wire Combination Smoke and Carbon Monoxide Detector, 120 Volt 9 Volt Battery Back-up - 3 Pack $239.99
$23999current price $239.99First Alert SC9120B Direct Wire Combination Smoke and Carbon Monoxide Detector, 120 Volt 9 Volt Battery Back-up - 3 Pack
344.8 out of 5 Stars. 34 reviewsShipping, arrives in 3+ days100+ bought since yesterday Kidde AC Plug-In Carbon Monoxide Detector with Battery Backup, CO Alarm with LED Light Indicators $27.47
100+ bought since yesterday
3 optionsAvailable in additional 3 options$2747current price $27.47Options from $27.47 – $164.82Kidde AC Plug-In Carbon Monoxide Detector with Battery Backup, CO Alarm with LED Light Indicators
14144.7 out of 5 Stars. 1414 reviewsSave withPickup todayDelivery todayShipping, arrives todayEnergizer MAX AA Batteries (48 Pack), Double A Alkaline Batteries $29.98 Was $36.25
Now$2998current price Now $29.98, Was $36.25$36.25You save $6.27You save$6.27Energizer MAX AA Batteries (48 Pack), Double A Alkaline Batteries
50764.8 out of 5 Stars. 5076 reviewsSave withShipping, arrives tomorrowEnergizer Ultimate Lithium AA Batteries (12 Pack), Double A Batteries $26.00 Was $78.27
Now$2600current price Now $26.00, Was $78.27$78.27You save $52.27You save$52.27Energizer Ultimate Lithium AA Batteries (12 Pack), Double A Batteries
21014.7 out of 5 Stars. 2101 reviewsSave withShipping, arrives tomorrowDuracell Coppertop 9V Battery, Long Lasting Batteries, 4 Pack $18.79 $4.70/ea
$1879current price $18.79$4.70/eaDuracell Coppertop 9V Battery, Long Lasting Batteries, 4 Pack
16674.7 out of 5 Stars. 1667 reviewsSave withShipping, arrives tomorrowBest seller Energizer MAX (24 Pack), Double A Batteries $16.49
Best seller
$1649current price $16.49Energizer MAX (24 Pack), Double A Batteries
103094.6 out of 5 Stars. 10309 reviewsSave withShipping, arrives tomorrowEnergizer Ultimate Lithium AA Batteries (8 Pack), Double A Batteries $20.28 Was $25.00 $2.54/ea
Now$2028current price Now $20.28, Was $25.00$25.00$2.54/eaYou save $4.72You save$4.72Energizer Ultimate Lithium AA Batteries (8 Pack), Double A Batteries
27044.7 out of 5 Stars. 2704 reviewsSave withShipping, arrives tomorrowBest seller Duracell Coppertop AAA Battery with POWER BOOSTâ„¢, 16 Pack Long-Lasting Batteries $14.69 Was $17.29
Best seller
3 optionsAvailable in additional 3 optionsNow$1469current price Now $14.69, Was $17.29$17.29You save $2.60You save$2.60Options from $14.69 – $29.38Duracell Coppertop AAA Battery with POWER BOOST™, 16 Pack Long-Lasting Batteries
74044.7 out of 5 Stars. 7404 reviewsSave withShipping, arrives today100+ bought since yesterday Duracell Coppertop AA Alkaline Batteries 8/PK $7.11 Was $13.49
100+ bought since yesterday
Now$711current price Now $7.11, Was $13.49$13.49You save $6.38You save$6.38Options from $7.11 – $8.26Duracell Coppertop AA Alkaline Batteries 8/PK
180094.7 out of 5 Stars. 18009 reviewsSave withShipping, arrives todayEnergizer MAX (16 Pack), Double A Batteries $10.79 Was $18.99
2 optionsAvailable in additional 2 optionsNow$1079current price Now $10.79, Was $18.99$18.99You save $8.20You save$8.20Options from $10.79 – $21.58Energizer MAX (16 Pack), Double A Batteries
84834.7 out of 5 Stars. 8483 reviewsSave withShipping, arrives today100+ bought since yesterday Duracell Coppertop AA Alkaline Batteries 24/PK $22.49 Was $28.82 93.7 ¢/ea
100+ bought since yesterday
Now$2249current price Now $22.49, Was $28.82$28.8293.7 ¢/eaYou save $6.33You save$6.33Duracell Coppertop AA Alkaline Batteries 24/PK
179744.7 out of 5 Stars. 17974 reviewsSave withShipping, arrives tomorrowDuracell Coppertop AA Battery with POWER BOOSTâ„¢, 16 Pack Long-Lasting Batteries $14.95
2 optionsAvailable in additional 2 options$1495current price $14.95Options from $14.95 – $31.94Duracell Coppertop AA Battery with POWER BOOST™, 16 Pack Long-Lasting Batteries
85394.7 out of 5 Stars. 8539 reviewsSave withShipping, arrives today100+ bought since yesterday Energizer Ultimate Lithium AA Batteries (4 Pack), Double A Batteries $9.95 Was $13.49
100+ bought since yesterday
Now$995current price Now $9.95, Was $13.49$13.49You save $3.54You save$3.54Energizer Ultimate Lithium AA Batteries (4 Pack), Double A Batteries
28884.7 out of 5 Stars. 2888 reviewsSave withShipping, arrives today
Customer ratings & reviews
How item rating is calculated
Customer images
Sort by |
Showing 1-3 of 39 reviews
Aug 18, 2024
WalmartCustomer
Item details
Size: 1
5 out of 5 stars review
Verified Purchase
The product was readily available and priced considerably lower than other merchants. Also, it's delivery time was impressive!
Incentivized Review
Helpful?1WORBDFZ8ZJL38219677
Mar 20, 2025
L
Item details
Size: 1
5 out of 5 stars review
Verified Purchase
Adapter made this much easier.
This was easy to install and came with more than one adapter so that the installation was fast and comparable with my old smoke detector.
Incentivized Review
Helpful?1WORBDFZ8ZJL38219677
Oct 12, 2024
Justin
Item details
Size: 1
5 out of 5 stars review
Verified Purchase
Effective smoke alarm without false positives
Easy to install, uses more common AA batteries rather than 9 volt batteries. Loud, interconnecting with other smoke alarms works great. Have not had issues of false alarms from steam with a nearby bathroom (shower steam).
Incentivized Review
Helpful?1WORBDFZ8ZJL38219677
Popular items in this category
Best selling items that customers love
BRK fg250b, Battery Dual Ionization Sensor Smoke Alarm $21.99
$2199current price $21.99BRK fg250b, Battery Dual Ionization Sensor Smoke Alarm
35 out of 5 Stars. 3 reviewsShipping, arrives in 3+ daysFirst Alert BRK FG250B Dual Ionization Smoke Alarm with 9-Volt Battery, 1", White $21.99
$2199current price $21.99First Alert BRK FG250B Dual Ionization Smoke Alarm with 9-Volt Battery, 1", White
394.4 out of 5 Stars. 39 reviewsShipping, arrives in 3+ daysKidde Hardwired Photoelectric Smoke Detector Alarm, AA Battery Backup, 5-inch $34.84
2 optionsAvailable in additional 2 options$3484current price $34.84Options from $34.84 – $63.00Kidde Hardwired Photoelectric Smoke Detector Alarm, AA Battery Backup, 5-inch
1383.7 out of 5 Stars. 138 reviewsSave withPickup todayDelivery todayShipping, arrives todaySITERWELL Hardwired Interconnected Smoke Detector, Photoelectric Smoke Alarm with 9V Backup Battery, Fire Alarm with Test/Silence Button, ETL Listed, GS562A, 1 Pack $81.99
9 optionsAvailable in additional 9 optionsSponsored$8199current price $81.99More options from $19.19SITERWELL Hardwired Interconnected Smoke Detector, Photoelectric Smoke Alarm with 9V Backup Battery, Fire Alarm with Test/Silence Button, ETL Listed, GS562A, 1 Pack
844.5 out of 5 Stars. 84 reviewsSave withShipping, arrives tomorrowFirst Alert 1046856, 10 Year Battery Ionization Smoke Alarm $24.59 Was $28.00
Now$2459current price Now $24.59, Was $28.00$28.00You save $3.41You save$3.41First Alert 1046856, 10 Year Battery Ionization Smoke Alarm
364.6 out of 5 Stars. 36 reviewsSave withShipping, arrives in 3+ daysFirst Alert Hardwired Smoke Alarm with Battery Backup 6 PACK $137.20
$13720current price $137.20First Alert Hardwired Smoke Alarm with Battery Backup 6 PACK
334.7 out of 5 Stars. 33 reviewsSave withShipping, arrives tomorrowBRK Battery-Powered Ionization Smoke and Carbon Monoxide Detector $39.97
$3997current price $39.97BRK Battery-Powered Ionization Smoke and Carbon Monoxide Detector
25 out of 5 Stars. 2 reviewsShipping, arrives in 3+ daysFirst Alert PRC710, Battery-Powered Ionization Smoke Alarms $18.67 Was $21.99
Now$1867current price Now $18.67, Was $21.99$21.99You save $3.32You save$3.32First Alert PRC710, Battery-Powered Ionization Smoke Alarms
194.5 out of 5 Stars. 19 reviewsSave withShipping, arrives in 3+ daysKidde Bedroom P3010B Battery Power Smoke with Voice Alert $32.94
$3294current price $32.94Kidde Bedroom P3010B Battery Power Smoke with Voice Alert
441.2 out of 5 Stars. 44 reviewsSave withFirst Alert Voice Alert Hard-Wired Photoelectric Smoke Detector $33.99
$3399current price $33.99First Alert Voice Alert Hard-Wired Photoelectric Smoke Detector
134.6 out of 5 Stars. 13 reviewsSave withShipping, arrives in 3+ daysFirst Alert 1046755, Battery Photoelectric Smoke Alarm $28.16
$2816current price $28.16First Alert 1046755, Battery Photoelectric Smoke Alarm
144.3 out of 5 Stars. 14 reviewsSave withShipping, arrives in 3+ daysFirst Alert 1046731, Battery Photoelectric Sensor Smoke Alarm $29.99 Was $35.05
Now$2999current price Now $29.99, Was $35.05$35.05You save $5.06You save$5.06First Alert 1046731, Battery Photoelectric Sensor Smoke Alarm
144.2 out of 5 Stars. 14 reviewsSave withShipping, arrives in 3+ daysBRK Hard-Wired w/Battery Back-Up Ionization Smoke and Carbon Monoxide Detector $54.99 Was $64.00
Now$5499current price Now $54.99, Was $64.00$64.00You save $9.01You save$9.01BRK Hard-Wired w/Battery Back-Up Ionization Smoke and Carbon Monoxide Detector
574.4 out of 5 Stars. 57 reviewsShipping, arrives in 3+ daysKidde Hardwired Photoelectric Smoke Detector Alarm, 10-Year Lithium Sealed Battery Backup $37.79
2 optionsAvailable in additional 2 options$3779current price $37.79Options from $37.79 – $75.58Kidde Hardwired Photoelectric Smoke Detector Alarm, 10-Year Lithium Sealed Battery Backup
1933.6 out of 5 Stars. 193 reviewsSave withPickup todayDelivery todayShipping, arrives today

