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First Alert

First Alert 10-Year Battery Combination Smoke & Carbon Monoxide Alarm

  • Based on 1,726 reviews
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Availability: In Stock.
Fulfilled by Amazon
Arrives Friday, Sep 18
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Style: Precision Detection


Pattern Name: SMCO210


Features

  • First Alert's Precision Detection advanced sensing technology complies with new industry standards to reduce cooking nuisance alarms and provides early warning in the event of a home fire emergency.
  • Provides reliable 2-in-1 protection against both smoke and carbon monoxide in an easy to install alarm
  • 10-Year sealed battery eliminates battery replacements and low battery chirps for the life of the alarm
  • End-of-life warning lets you know when its time to replace the alarm
  • Slim profile design is half the depth of a standard alarm

Description

The First Alert SMCO210 10-Year Sealed Battery Combination Smoke & Carbon Monoxide Alarm with Slim Profile Design uses First Alert's Precision Detection advanced sensing technology and meets new industry standards. This 2-in-1 alarm provides convenient protection against both fire and carbon monoxide (CO). Also equipped with a 10-year sealed battery to eliminate the need for battery replacements and low battery chirps.

Brand: First Alert


Style: Precision Detection


Power Source: Battery Powered


Color: White


Product Dimensions: 5.67"D x 5.67"W x 1"H


Item Weight: 6.56 ounces


Alarm: Combination Alarm


Operating Humidity: 10-95% RH


Sensor Type: Photoelectric


Material: Plastic


Brand: First Alert


Model Number: SMCO210


Manufacturer Warranty Description: Warranty


Unit Count: 1 Count


Number of Items: 1


Item Highlight: SMCO210 Slim Profile Design, Sealed Battery


Manufacturer: Resideo


UPC: 029054022233


Item Type Name: Combination Alarm


Mfr Part Number: SMCO210


Power Source: Battery Powered


Alarm: Combination Alarm


Sensor Type: Photoelectric


Operating Humidity: 10-95% RH


Product Style: Precision Detection


Color: White


Item Dimensions D x W x H: 5.67"D x 5.67"W x 1"H


Item Weight: 6.56 ounces


Enclosure Material: Plastic


Frequently asked questions

If you place your order now, the estimated arrival date for this product is: Friday, Sep 18

Yes, absolutely! You may return this product for a full refund within 30 days of receiving it.

To initiate a return, please visit our Returns Center.

View our full returns policy here.

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Top Amazon Reviews

    • I buy again
Style: Precision Detection Pattern Name: SMCO210
Work as it should has a 10 year battery after 10 years the detector will stop working
Reviewed in the United States on May 17, 2026 by tyer
    • Do not buy! False alarms lasting 2 minutes. Absolute nightmare.
Style: Precision Detection Pattern Name: SMCO210
I bought 5 of these when I moved into a home I bought a couple of years ago. On 3 different occasions, 3 different fire alarms had false alarms. These false alarms last 2 minutes and in my case occurred in the middle of the night. On many occasions, my wife and I would wake up in abject horror. Adrenaline dumping into our system as I jump up and try to find the source of the sound. As soon as I run downstairs it stops. I check around the house. Check the other smoke alarms, calm down and go to bed. Only to be woken up again in an hour. Finally, I figured out that these first alert alarms are the issue. The fun part is they are sealed and cant be turned off. So how do you stop them from keeping you up? No other solution but a hammer. You take it off the wall and bring it outside and break it in a million pieces. After realizing that these are garbage, I threw away 4 of them. But I forget the 5th one which was in the basement, in a room with a c02/smoke alarm from a better company. Sure enough, 2 years later, at 2:30am the piece of junk goes off for two minutes then goes silent. I just out of bed in horror, unable to find it before it stops. After the second time, i realize the sound is coming from the basement. I go down there and see that stupid first alert logo looking at me and realize that I have forgotten this last unit was year when I smashed the others two years ago. So I break out the old hammer and put it out of mine and its misery. To be clear- I have several redundant c02/smoke alarms from other companies in the house that havent gone off. So this is not a case of there being c02 or smoke that I have missed. These are just garbage. I have never written a bad review on amazon. Just this one. To say that I will never touch another first alert product in my life doesnt come close to the animosity I have for this product. ... show more
Reviewed in the United States on August 13, 2025 by Tom
    • Good product
Style: Precision Detection Pattern Name: SMCO210
Works like a charm
Reviewed in the United States on August 21, 2026 by Jeremy McKeon
    • As advertised
Style: Precision Detection Pattern Name: SMCO210
As advertised
Reviewed in the United States on August 22, 2026 by br3lmm
    • Great when it works
Style: Precision Detection Pattern Name: SMCO210
Had to return the first one because it was not operating correctly right out of the box. But the replacement came quickly, ready, and working. Easy to install.
Reviewed in the United States on May 29, 2025 by Megan
    • Complete garbage
Style: Precision Detection Pattern Name: SMCO210
If I could give these no stars I would. I purchased 2 of these in Feb to replace some old wired smoke detectors. Install was easy. The trouble came in Sept when one of them started to malfunction and give an alarm all the time when there was no smoke or heavy fumes. Nothing. Also it was not a CO alarm but a smoke. At all hours of the day and night. I finally got so sick of it that I pulled it off the ceiling and wrapped it in a blanket as my poor dog was shaking violently every time it went off. Put it back up a week later. Same problem. So I tossed it. Now here we are in Nov and the other one I bough is doing the same thing. Going off for no reason. Even wrapped in a blanket it was still going off. So I put it out on the porch. With fresh air and everything. And it continued to go off sitting outside intermittently for 2 more days before it too went in the trash. We are of course outside the return window. So I spent $80 to not have any smoke detectors in the house and will have to shell out more money again to buy another brand. These werent old. Both had been up less then 9 months when they malfunctioned. Dont waste your money on these unless you like your pets being traumatized at 2am when the thing randomly goes off for no reason and wont stop. ... show more
Reviewed in the United States on November 2, 2025 by Brittany B
    • So Thankful We Found a Replacement!!!
Style: Precision Detection Pattern Name: SMCO210
Perfect. When NEST pulled out of the Fire & CO Detector business, we scrambled to figure out what to do after many years. We turned to Amazon, saw this, ordered 2 and everything is perfect. Whew. A huge weight off our minds. Thank you First Alert and thank you Amazon.
Reviewed in the United States on June 26, 2026 by Chicago Customer
    • 10yr battery life. That's a lifesaver by itself.
Style: Precision Detection Pattern Name: SMCO210
Well Made and has long lasting battery. Highly rated in CR safety products. I would recommend this product.
Reviewed in the United States on July 11, 2026 by JoeTF,Louisiana

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