Search  for anything...
First Alert

First Alert SMCO210, 10-Year Sealed Battery Combination Smoke & Carbon Monoxide Alarm with Slim Profile Design, 1-Pack

  • Based on 1,480 reviews
Condition: New
Checking for the best price...
$37.01 Why this price?
Save $22.98 was $59.99

Buy Now, Pay Later

As low as $9 / mo
  • – 4-month term
  • – No impact on credit to apply
  • – Instant approval decision
  • – Secure and straightforward checkout

Ready to go? Add this product to your cart and select a plan during checkout.

Payment plans are offered through our trusted finance partners Klarna, Affirm, Afterpay, Apple Pay, and PayTomorrow. No-credit-needed leasing options through Acima may also be available at checkout.

Learn more about financing & leasing here.

Selected Option

Free shipping on this product

FREE 30-day refund/replacement

To qualify for a full refund, items must be returned in their original, unused condition. If an item is returned in a used, damaged, or materially different state, you may be granted a partial refund.

To initiate a return, please visit our Returns Center.

View our full returns policy here.

Availability: In Stock.
Fulfilled by Amazon
Arrives Tuesday, Jun 30
Order within 16 hours and 15 minutes
Available payment plans shown during checkout
Protection Plan Protect Your Purchase
Checking for protection plans...

Recently Viewed

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


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


Brand: First Alert


Model Number: SMCO210


Manufacturer Warranty Description: Warranty


Number of Items: 1


Manufacturer: Resideo


UPC: 029054022233


Mfr Part Number: SMCO210


Unit Count: 1.0 Count


Item Type Name: Combination Alarm


Frequently asked questions

If you place your order now, the estimated arrival date for this product is: Tuesday, Jun 30

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.

  • Klarna Financing
  • Affirm Pay in 4
  • Affirm Financing
  • Afterpay Financing
  • PayTomorrow Financing
  • Financing through Apple Pay
Leasing options through Acima may also be available during checkout.

Learn more about financing & leasing here.

Similar Products

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
    • NOT WORTH IT! Literal junk and a waste of money, not gonna keep your family safe πŸ‘ŽπŸ»
Style: Precision Detection Pattern Name: SMCO210
I can’t believe what a disappointment this alarm is. Random false fire alarms defeats the purpose of having one. It scared my dog really bad too. I am so upset by this I felt inclined to warn the public. I guess it’s common in these newer models from what I read. The back of the alarm states that the alarm cannot be reactivated once you deactivate it. Lies. I was able to switch that on and off, which I’m guessing it’s not supposed to do. I used to trust this brand, as I had some of their alarms in the past with no issues, but now I question the entire brand. You can register the alarm and request replacement, but they gonna replace it with one that actually works though? My faith in first alert is shattered, and I’m afraid I can’t trust this brand anymore. I am now out the money and need to seek out a reliable brand so I can keep my family safe. Fast-fashion-style piece of junk alarm. Just pumping out trash and calling them fire alarms. πŸ‘ŽπŸ»πŸ‘ŽπŸ»πŸ‘ŽπŸ»πŸ‘ŽπŸ»πŸ‘ŽπŸ» ... show more
Reviewed in the United States on May 13, 2026 by Harlie Nelson
    • Affordable and adequate
Style: Precision Detection Pattern Name: SMCO210
Easy to Install
Reviewed in the United States on May 29, 2026 by HEIDI PETER
    • No batteries
Style: Precision Detection Pattern Name: SMCO210
The two in one is great to have no batteries too
Reviewed in the United States on June 8, 2026 by Teresa O.
    • A good product but incomplete
Style: Precision Detection Pattern Name: SMCO210
I believe the product will work well. I received no screws or mollies for the install.
Reviewed in the United States on May 29, 2026 by Amazon Customer
    • Needs to be installed
Style: Precision Detection Pattern Name: SMCO210
Hasn’t gone off yet.
Reviewed in the United States on June 10, 2026 by Peter Green
    • 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
    • Helpful
Style: Precision Detection Pattern Name: SMCO210
Perfect
Reviewed in the United States on June 5, 2026 by Samuel Spencer

Can't find a product?

Find it on Amazon first, then paste the link below.
Checking for best price...