2nd May 2026, 03:20 PM
First Alert 9120B / SMI100-AC Smoke Detector, Hardwired Alarm with Battery Backup, 3-Pack
Price may vary by location, shipping cost, and availability.
27% Off
$52.99
$72.99
Highest: $68.85
Average: $38.67
Lowest: $25.79
Price History Graph
Offer Price Prices
Lowest: -
Average: -
Highest: -
Price History Information
You can check the price history of First Alert 9120B / SMI100-AC Smoke Detector, Hardwired Alarm with Battery Backup, 3-Pack here. This product's current Price in USA is $52.99. The average and highest prices are $38.67 and $68.85 respectively.
| Lowest Ever Price | $25.79 |
|---|---|
| 11th May 2022 | |
| Average Price | $38.67 |
| Based on 2841 days price tracking | |
| Highest Price | $68.85 |
| 8th Aug 2024 | |
Price History of All Variants of First Alert 9120B SMI100-AC Smoke Detector...
Current Price in USA
| Price | $52.99 |
|---|---|
| MRP | $72.99 |
| Savings | $20.00 |
| Discount | 27.40% |
Recent Price Drops on First Alert 9120B / SMI100-AC Smoke Detector, Hardwired Alarm with Battery Backup, 3-Pack
Price Drop 5th Jan 2026
$54.79 → $51.26
6.44% drop
Price Drop 3rd Nov 2025
$55.10 → $51.26
6.97% drop
Price Drop 7th Jul 2025
$56.01 → $51.55
7.96% drop
Price Drop 6th Jul 2025
$56.25 → $51.55
8.36% drop
Price Drop 1st Jul 2025
$56.90 → $51.55
9.4% drop
Price Drop 29th Jun 2025
$55.82 → $51.55
7.65% drop
Price Drop 27th Jun 2025
$56.86 → $51.55
9.34% drop
Price Drop 2nd Feb 2025
$66.77 → $55.00
17.63% drop
Price Drop 28th Jan 2025
$66.70 → $55.00
17.54% drop
Price Drop 10th Sep 2024
$57.98 → $49.79
14.13% drop
Price Drop 3rd Sep 2024
$52.48 → $40.99
21.89% drop
Price Drop 29th Aug 2024
$56.99 → $53.00
7% drop
Price Drop 20th Aug 2024
$59.90 → $55.90
6.68% drop
Price Drop 14th Aug 2024
$59.99 → $47.57
20.7% drop
Price Drop 8th Aug 2024
$68.85 → $55.99
18.68% drop
Price Drop 4th Aug 2024
$55.99 → $52.98
5.38% drop
Price Drop 15th Jul 2024
$56.99 → $48.99
14.04% drop
Price Drop 10th Jul 2024
$56.99 → $44.60
21.74% drop
Price Drop 30th Jun 2024
$49.99 → $46.15
7.68% drop
Price Drop 23rd Jun 2024
$48.99 → $44.00
10.19% drop
Price Drop 19th Jun 2024
$45.00 → $42.60
5.33% drop
Price Drop 9th May 2024
$38.03 → $34.99
7.99% drop
Price Drop 6th May 2024
$38.03 → $34.99
7.99% drop
Price Drop 30th Jan 2024
$38.05 → $36.00
5.39% drop
Price Drop 21st Aug 2023
$37.00 → $34.15
7.7% drop
Price Drop 11th Aug 2023
$37.00 → $34.99
5.43% drop
Price Drop 7th Jun 2023
$36.50 → $29.99
17.84% drop
Price Drop 19th May 2023
$36.95 → $35.10
5.01% drop
Price Drop 11th May 2023
$36.95 → $35.10
5.01% drop
Price Drop 29th Mar 2023
$34.99 → $32.99
5.72% drop
Price Drop 26th Feb 2023
$36.99 → $34.99
5.41% drop
Price Drop 15th Feb 2023
$37.13 → $34.99
5.76% drop
Price Drop 12th Feb 2023
$37.13 → $34.99
5.76% drop
Price Drop 17th Jan 2023
$37.13 → $34.90
6.01% drop
Price Drop 1st Jan 2023
$37.13 → $34.90
6.01% drop
Price Drop 29th Dec 2022
$37.13 → $34.80
6.28% drop
Price Drop 9th Nov 2022
$36.59 → $32.99
9.84% drop
Price Drop 12th Aug 2022
$34.89 → $25.79
26.08% drop
Price Drop 5th Aug 2022
$34.89 → $25.79
26.08% drop
Price Drop 27th Jul 2022
$35.20 → $25.79
26.73% drop
Price Drop 23rd Jul 2022
$35.60 → $25.79
27.56% drop
Price Drop 29th Jun 2022
$36.49 → $25.79
29.32% drop
Price Drop 13th May 2022
$36.19 → $25.79
28.74% drop
Price Drop 10th May 2022
$32.29 → $25.79
20.13% drop
Price Drop 4th Apr 2022
$35.25 → $32.29
8.4% drop
Price Drop 29th Dec 2021
$35.99 → $32.29
10.28% drop
Price Drop 24th Nov 2021
$35.40 → $32.66
7.74% drop
Price Drop 11th Sep 2021
$32.99 → $31.10
5.73% drop
Price Drop 3rd Sep 2021
$37.52 → $33.69
10.21% drop
Price Drop 18th Aug 2021
$35.83 → $33.69
5.97% drop
Price Drop 25th Jul 2021
$33.50 → $31.78
5.13% drop
Price Drop 29th May 2021
$32.94 → $28.60
13.18% drop
Price Drop 16th Apr 2021
$33.13 → $30.00
9.45% drop
Price Drop 6th Apr 2021
$33.87 → $31.99
5.55% drop
Price Drop 5th Mar 2021
$34.85 → $32.23
7.52% drop
Price Drop 9th Nov 2020
$33.86 → $30.48
9.98% drop
Price Drop 19th Oct 2020
$38.99 → $34.55
11.39% drop
Price Drop 13th Sep 2020
$43.98 → $39.99
9.07% drop
Price Drop 30th Aug 2020
$42.98 → $39.55
7.98% drop
Price Drop 27th Aug 2020
$41.98 → $39.55
5.79% drop
Price Drop 22nd Aug 2020
$41.98 → $39.55
5.79% drop
Price Drop 8th Aug 2020
$36.63 → $34.65
5.41% drop
Price Drop 3rd Aug 2020
$37.77 → $34.97
7.41% drop
Price Drop 1st Jul 2020
$41.98 → $39.56
5.76% drop
Price Drop 27th Jun 2020
$41.98 → $39.66
5.53% drop
Price Drop 21st Jun 2020
$41.98 → $39.66
5.53% drop
Price Drop 8th Jun 2020
$38.99 → $36.76
5.72% drop
Price Drop 24th May 2020
$38.94 → $35.95
7.68% drop
Price Drop 18th Apr 2020
$38.60 → $34.99
9.35% drop
Price Drop 18th Mar 2020
$38.13 → $34.99
8.23% drop
Price Drop 8th Feb 2020
$34.99 → $29.99
14.29% drop
Price Drop 5th Nov 2019
$36.22 → $32.17
11.18% drop
Price Drop 4th Apr 2019
$36.26 → $29.76
17.93% drop
Price Drop 14th Mar 2019
$36.26 → $32.32
10.87% drop
Price Drop 2nd Feb 2019
$36.69 → $33.05
9.92% drop
Price Drop 22nd Nov 2018
$36.69 → $33.98
7.39% drop
Price Drop 30th Sep 2018
$38.99 → $36.72
5.82% drop
Price Drop 26th Sep 2018
$45.91 → $38.99
15.07% drop
Price Drop 28th Aug 2018
$45.79 → $42.99
6.11% drop
Price Drop 21st Aug 2018
$45.90 → $42.99
6.34% drop
Product Information
Details
| Product Name | First Alert 9120B / SMI100-AC Smoke Detector, Hardwired Alarm with Battery Backup, 3-Pack |
|---|---|
| Store Product Code | B07B4CG1PG |
| Store Name | amazon.com |
| Brand | First Alert |
| Rating | 9.4 / 10 |
| Category | Smoke Detectors & Fire Alarms |
| Product Manufacturer | First Alert |
| Model Number | BRK 9120B-3 |
| Color | White |
| Size | 3-Pack |
| Dimensions | 1.9"D x 5.6"W x 5.6"H |
Features
- Keep your family safe with this 3 pack of hardwired smoke alarms; the battery backup means constant monitoring, even if there's a power failure
- Equipped with an ionization sensor, this smoke alarm reliably detects smoke from fast flaming fires and alerts you with an 85 decibel alarm
- To ensure complete protection make sure to place one on each level of your home and in each bedroom
- Can connect to other compatible BRK or First Alert smoke detectors, to ensure all alarms will sound when smoke 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
- Rigorously tested to meet UL standards
- Faster turnarounds on job sites with the easy to install, most trusted alarms in home safety
- First Alert has been the most trusted brand in home safety since launching the first residential smoke alarm in 1958 (Based on a First Alert Brand Trust Survey in February 2018)
Images
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Rating and Reviews
9.4 Based on 4551 reviews
First Alert 9120B SMI100-AC Smoke Detector has 9.4 rating out of 10. This average rating is consist of 4551 individual ratings. You can rate this product at product review page.
* Predictions is created on based of past prices and trends, it does not guarantee that it will happen. These are just prediction for theoretical information only.