--- product_id: 770784697 title: "First Alert BRK 3120B Hardwire Dual Photoelectric and Ionization Sensor Smoke Alarm with Battery Backup" brand: "first alert" price: "AR$5637" currency: ARS in_stock: false reviews_count: 5 url: https://www.desertcart.com.ar/products/770784697-first-alert-brk-3120b-hardwire-dual-photoelectric-and-ionization-sensor store_origin: AR region: Argentina --- # Optipath 360° patented access 8760h battery life Dual photoelectric + ionization sensors First Alert BRK 3120B Hardwire Dual Photoelectric and Ionization Sensor Smoke Alarm with Battery Backup **Brand:** first alert **Price:** AR$5637 **Availability:** ❌ Out of Stock ## Summary > 🔥 Stay ahead of danger with 360° smart safety! 🔋 ## Quick Answers - **What is this?** First Alert BRK 3120B Hardwire Dual Photoelectric and Ionization Sensor Smoke Alarm with Battery Backup by first alert - **How much does it cost?** AR$5637 with free shipping - **Is it available?** Currently out of stock - **Where can I buy it?** [www.desertcart.com.ar](https://www.desertcart.com.ar/products/770784697-first-alert-brk-3120b-hardwire-dual-photoelectric-and-ionization-sensor) ## 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 - • **Smart Alerts:** Dual latching indicators pinpoint low battery or alarm source instantly. - • **Effortless Control:** One-button test and silence for monthly peace of mind and false alarm ease. - • **Power When You Need It:** Hardwired with battery backup ensures nonstop protection, even during outages. - • **360° Access Innovation:** Patented Optipath 360 design makes maintenance and monitoring a breeze. - • **Unmatched Fire Detection:** Dual sensor tech covers all fire types for ultimate safety. ## Overview The First Alert BRK 3120B is a hardwired smoke alarm featuring dual photoelectric and ionization sensors for comprehensive fire detection. It includes a battery backup with an impressive 8760-hour lifespan to maintain protection during power outages. The patented Optipath 360 technology allows easy access for testing and maintenance, while a single button simplifies monthly testing and silencing false alarms. Dual latching indicators provide clear alerts for low battery or alarm origin, making it a reliable and user-friendly safety device. ## Description Hardwired alarm includes battery backup for power outages Photoelectric and ionization sensors provide comprehensive fire detection A single button makes alarm easy to test monthly or silence during a false alarm Two latching features help indicate a low battery or the originating alarm in a system Optipath 360 patented technology provides 360 degrees of access to the smoke alarm Review: Reliable Smoke Protection Without the Hassle of Battery Changes - Reliable Smoke Protection Without the Hassle of Battery Changes I’ve been gradually upgrading the smoke alarms in my home, and this First Alert SM310 has been one of the easiest and most reassuring additions. The 10-year sealed lithium battery is a huge selling point—no more late-night chirping or running out for 9V batteries. Once mounted, it’s basically set-and-forget until replacement time. What I really appreciate is the dual-sensor design. It combines photoelectric and ionization sensors, which means it’s better equipped to detect both fast-flaming and smoldering fires. That gives me more peace of mind, especially with kids in the house and multiple floors to cover. The test/silence button is also handy—easy to reach, and it worked perfectly during my trial run. Installation was quick with the included hardware, and the alarm sits low-profile against the ceiling without looking bulky. The sound output is loud enough to be jarring (as it should be), easily heard through closed doors. If I had to nitpick, I’d say it’s not interconnected, so it won’t set off other alarms in the house if one goes off. For some setups, that’s an important feature to consider. But for standalone coverage—especially in bedrooms, hallways, and smaller homes—it’s an excellent choice. Bottom line: A dependable, no-maintenance smoke alarm with dual sensors and a 10-year battery that delivers both convenience and safety. Review: Solid smoke detector and easy to install - As a volunteer firefighter, I look at smoke detectors as an insurance policy. I bought six of these to replace the existing smoke detectors in our eight year old home. The previous detectors started to fail causing random activation at the worst possible times. Think 3 am being fast asleep and the alarms would go off. Batteries changed, old detectors cleaned out with an air duster and still no luck. Since its wise to replace your detectors every ten years or so, I bit the bullet and replaced them all. The wiring in my house allows these to be daisy chained (when one detector is activated a signal is sent to the rest via the house's smoke detection power source) with one another which in my opinion is a good thing. I want to know if a fire has started in another part of the house and the unit closest to me to activate as well. As for this product, it is a little more expensive than other units, but it is well worth it for its dual detection capabilities: photo electric and ionization. They are extremely easy to install and come with all of the necessary hardware. Most houses built in the last 15 years or so have been wired for smoke alarms and these units run off that power source. They come with a low voltage terminal/wire that can be adapted easily to your system if your system has the old contacts. One of the main selling points for me is that the backup power on these units use AA batteries instead of a 9 volt which is the majority of other units. I also purchased two combination smoke alarm/carbon monoxide detectors that are compatible with these units in a systems configuration. All things aside, no more false latch alarms and new units installed that should last me another ten years in the house. ## Features - Hardwired alarm includes battery backup for power outages - Photoelectric and ionization sensors provide comprehensive fire detection - A single button makes alarm easy to test monthly or silence during a false alarm - Two latching features help indicate a low battery or the originating alarm in a system - Optipath 360 patented technology provides 360 degrees of access to the smoke alarm ## Technical Specifications | Specification | Value | |---------------|-------| | ASIN | B00O8MVW44 | | Alarm | Visual | | Battery Average Life | 8760 Hours | | Brand | First Alert | | Customer Reviews | 4.4 out of 5 stars 2,064 Reviews | | Global Trade Identification Number | 00029054015334 | | Item Weight | 331 g | | Item weight | 331 g | | Manufacturer | First Alert | | Model Number | 3120FF | | Number of Items | 1 | | Part Number | 3120FF | | Power source | Battery Powered , Corded Electric | | Product Style | Classic | | Sensor Type | Photoelectric | | Sensor type | Photoelectric | | Style | Classic | | UPC | 029054015334 | | Unit Count | 1.0 count | ## Product Details - **Alarm:** Visual - **Brand:** First Alert - **Global Trade Identification Number:** 00029054015334 - **Item weight:** 331 g - **Manufacturer:** First Alert - **Number of items:** 1 - **Power source:** Battery Powered, Corded Electric - **Sensor type:** photoelectric - **Style:** Classic - **UPC:** 029054015334 ## Images ![First Alert BRK 3120B Hardwire Dual Photoelectric and Ionization Sensor Smoke Alarm with Battery Backup - Image 1](https://m.media-amazon.com/images/I/71oXRzJAN7L.jpg) ![First Alert BRK 3120B Hardwire Dual Photoelectric and Ionization Sensor Smoke Alarm with Battery Backup - Image 2](https://m.media-amazon.com/images/I/61rdkdw39jL.jpg) ![First Alert BRK 3120B Hardwire Dual Photoelectric and Ionization Sensor Smoke Alarm with Battery Backup - Image 3](https://m.media-amazon.com/images/I/71on85lGNsL.jpg) ![First Alert BRK 3120B Hardwire Dual Photoelectric and Ionization Sensor Smoke Alarm with Battery Backup - Image 4](https://m.media-amazon.com/images/I/81SkbT2j70L.jpg) ![First Alert BRK 3120B Hardwire Dual Photoelectric and Ionization Sensor Smoke Alarm with Battery Backup - Image 5](https://m.media-amazon.com/images/I/61XcWXuGmUL.jpg) ## Questions & Answers **Q: How does the Alarm Latch feature "easily identify initiating alarm"? This is major problem with false alarms on my existing Kidde/Firex dual alarms.** A: The unit that initiated the alarm will display a red light instead of green (while the others remain green). The same is true for the low battery latch - the unit with the low battery will flash green instead of having a steady green light. We had one unit (of 9) that kept false alarming when first installed, but we had just completed a renovation so may have been due to dust. It was nice to easily identify which unit initiated the alarm. No problems since replacing that one unit. **Q: How do these units interconnect? Hard wiring required?** A: The unit alarms are connected via a fourth wire in the AC cable. A three conductor cable with ground is the normal cable used ( likely 14/3 romex). The white wire is the neutral, the black wire is 125 volt hot side, the bare copper wire is the ground wire and then there should be a red wire that is used to tie the alarms together. The units are generally feed from a separate breaker. **Q: My house has FireX FADC Ionization Detectors, Can I mix dual sensors detectors with them?** A: Yes **Q: Is this model interconnectible with the first alert SC9120b? Will these units communicate with each other?** A: First Alert's manuals don't always list all the detectors they are compatible with. I believe this 3120B is compatible with your 9120B. Here's my logic: 1) I have a 3120B and a 7010B. They work together. 2) I looked at the owner's manual for your 9120B on the BRK website. It says the device works with the 7010B. 3) If 9120B and 7010B work together and if 3120B & 7010B work together, then it follows that 9120B and 3120B should work together. By the way, I used this same logic to determine that my 3120B and my 7010B would work together because they both worked with my older 4120B's and, sure enough, they did.You could always call BRK to confirm.Good luck! ## Customer Reviews ### ⭐⭐⭐⭐⭐ Reliable Smoke Protection Without the Hassle of Battery Changes *by E***S on 5 September 2025* Reliable Smoke Protection Without the Hassle of Battery Changes I’ve been gradually upgrading the smoke alarms in my home, and this First Alert SM310 has been one of the easiest and most reassuring additions. The 10-year sealed lithium battery is a huge selling point—no more late-night chirping or running out for 9V batteries. Once mounted, it’s basically set-and-forget until replacement time. What I really appreciate is the dual-sensor design. It combines photoelectric and ionization sensors, which means it’s better equipped to detect both fast-flaming and smoldering fires. That gives me more peace of mind, especially with kids in the house and multiple floors to cover. The test/silence button is also handy—easy to reach, and it worked perfectly during my trial run. Installation was quick with the included hardware, and the alarm sits low-profile against the ceiling without looking bulky. The sound output is loud enough to be jarring (as it should be), easily heard through closed doors. If I had to nitpick, I’d say it’s not interconnected, so it won’t set off other alarms in the house if one goes off. For some setups, that’s an important feature to consider. But for standalone coverage—especially in bedrooms, hallways, and smaller homes—it’s an excellent choice. Bottom line: A dependable, no-maintenance smoke alarm with dual sensors and a 10-year battery that delivers both convenience and safety. ### ⭐⭐⭐⭐⭐ Solid smoke detector and easy to install *by K***N on 5 February 2016* As a volunteer firefighter, I look at smoke detectors as an insurance policy. I bought six of these to replace the existing smoke detectors in our eight year old home. The previous detectors started to fail causing random activation at the worst possible times. Think 3 am being fast asleep and the alarms would go off. Batteries changed, old detectors cleaned out with an air duster and still no luck. Since its wise to replace your detectors every ten years or so, I bit the bullet and replaced them all. The wiring in my house allows these to be daisy chained (when one detector is activated a signal is sent to the rest via the house's smoke detection power source) with one another which in my opinion is a good thing. I want to know if a fire has started in another part of the house and the unit closest to me to activate as well. As for this product, it is a little more expensive than other units, but it is well worth it for its dual detection capabilities: photo electric and ionization. They are extremely easy to install and come with all of the necessary hardware. Most houses built in the last 15 years or so have been wired for smoke alarms and these units run off that power source. They come with a low voltage terminal/wire that can be adapted easily to your system if your system has the old contacts. One of the main selling points for me is that the backup power on these units use AA batteries instead of a 9 volt which is the majority of other units. I also purchased two combination smoke alarm/carbon monoxide detectors that are compatible with these units in a systems configuration. All things aside, no more false latch alarms and new units installed that should last me another ten years in the house. ### ⭐⭐⭐⭐⭐ First Alert BRK 3120B Combo Sensor (Photo and Ionization) Smoke Alarm - It's a Winner *by B***N on 7 February 2017* I had an older model BRK 4120B, about 10 years old, which only has one type of sensor. Ionization Smoke Alarms work best at detecting minute particles of fast, flaming fires, but there’s a tradeoff. These typical perform poorly in detecting smoky or smoldering fires. Ionization units have been reported to “false alarm” from charred food, liked an over-nuked pizza, while cooking. Photoelectric Smoke Alarms excel at detecting the bigger particles found in smoldering fires. Photoelectric units generally produce fewer “false alarms” from cooking, but react quickly detecting the smoldering fire types. The First Alert BRK 3120B offers the best of both worlds, using both Ionization and Photoelectric sensors. This way, you’ll get an alarm that detects either type of fire. Some newer Smoke Alarms, except the combo units, also have a built in CO Alarm. At first blush, I thought this might be the way to go, but call me old school, in that I believe it’s better to keep things simple, by having separate Smoke Detector and CO Detectors. Especially, since there are no combo smoke detectors and CO alarms all built in the same unit. My analogy is like when TV’s with integrated VCR’s first came on the scene. (I said I was old school). The TV make work fine, but if the VCR craps out – or vice versa, then you’re faced with a bit of a challenge, an also a higher repair cost, since all the componentry is smaller since it must all fit into the TV “box.” I also checked the rating for the BRK3120B and the Kidde PI2010, also a combo unit. I went with the First Alert because it offered the same reported lab performance at cost savings compared to Kidde. I need 12 alarms, so the cost savings essential got me 12 for the price of 10 from the other guys. Installation was especially easy, since the BRK uses the same size mounting ring (and the quick connect cable) as the ones I am replacing. Not a big deal, but nice nonetheless. Also, maybe a minor point, but the BRK 3120B uses 2 AA Alkaline batteries, compared to the more expensive 9V for the Kidde units. Lastly, be sure to replace any brand of smoke detectors after 10 years from their manufacturing date (usually found on the back of the alarm). Good Luck - I hope this helps. ## Frequently Bought Together - First Alert BRK 3120B Hardwired Photoelectric and Ionization Smoke Alarm with Battery Backup, Dual Sensing Smoke Alarm, 1-Pack - FIRST ALERT BRK 3120B-3 Hardwired Smoke Detector with Photoelectric and Ionization with Battery Backup, 3-Pack - First Alert SMICO100-AC Interconnect Hardwire Combination Smoke & Carbon Monoxide Alarm with Battery Backup, 1-Pack --- ## Why Shop on Desertcart? - 🛒 **Trusted by 1.3+ Million Shoppers** — Serving international shoppers since 2016 - 🌍 **Shop Globally** — Access 737+ million products across 21 categories - 💰 **No Hidden Fees** — All customs, duties, and taxes included in the price - 🔄 **15-Day Free Returns** — Hassle-free returns (30 days for PRO members) - 🔒 **Secure Payments** — Trusted payment options with buyer protection - ⭐ **TrustPilot Rated 4.5/5** — Based on 8,000+ happy customer reviews **Shop now:** [https://www.desertcart.com.ar/products/770784697-first-alert-brk-3120b-hardwire-dual-photoelectric-and-ionization-sensor](https://www.desertcart.com.ar/products/770784697-first-alert-brk-3120b-hardwire-dual-photoelectric-and-ionization-sensor) --- *Product available on Desertcart Argentina* *Store origin: AR* *Last updated: 2026-10-18*