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First Alert

First Alert SM210, 10-Year Sealed Battery Smoke Alarm with Slim Profile Design, 1-Pack

  • Based on 5,066 reviews
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Availability: In Stock.
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Arrives Monday, May 4
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Size: 1-Pack


Style: Precision Detection


Pattern Name: SM210


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.
  • 10-Year sealed battery eliminates battery replacements and low battery chirps for the life of the alarm
  • Slim profile design is half the depth of a standard alarm
  • End-of-life warning lets you know when its time to replace the alarm
  • Test/silence button for efficient testing to ensure alarm is working properly

Description

The First Alert SM210 10-Year Sealed Battery Smoke Alarm with Slim Profile Design is equipped with First Alert's Precision Detection advance sensing technology and meets new industry standards. This slim profile smoke alarm is easy to install, and the 10-year sealed battery means no battery replacements are required.

Brand: First Alert


Style: Precision Detection


Power Source: Battery Powered


Color: White


Product Dimensions: 5.13"D x 5.13"W x 1"H


Item Weight: 0.37 Pounds


Alarm: Smoke Alarm


Operating Humidity: 10-95% RH


Sensor Type: Photoelectric


Number of Items: 1


Brand: ‎First Alert


Style: ‎Precision Detection


Power Source: ‎Battery Powered


Color: ‎White


Product Dimensions: ‎5.13"D x 5.13"W x 1"H


Item Weight: ‎0.37 Pounds


Alarm: ‎Smoke Alarm


Operating Humidity: ‎10-95% RH


Sensor Type: ‎Photoelectric


Number of Items: ‎1


Manufacturer: ‎Resideo


UPC: ‎029054021847


Part Number: ‎SM210


Item Weight: ‎5.9 ounces


Item model number: ‎SM210


Batteries: ‎1 Product Specific batteries required. (included)


Size: ‎1-Pack


Pattern: ‎SM210


Item Package Quantity: ‎1


Batteries Included?: ‎Yes


Batteries Required?: ‎Yes


Battery Cell Type: ‎Lithium


Date First Available: September 22, 2023


Frequently asked questions

If you place your order now, the estimated arrival date for this product is: Monday, May 4

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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Similar Products

Top Amazon Reviews

    • Quality, dependability, and peace of mind.
Size: 1-Pack Style: Precision Detection Pattern Name: SM210
I needed to replace one wired and one battery smoke alarm. The original First Alert unit was no longer available, so we opted for the recommended unit. It arrived in a plain cardboard box, but the device was sealed. We had to change the mounting bracket to adapt to the newer design, but the size and function remained the same. All in all, a good quality alarm that will hopefully last the same 10 years as the original. ... show more
Reviewed in the United States on January 19, 2026 by empty in PHX
    • Smoke alarm
Size: 1-Pack Style: Standard Detection Pattern Name: PR710
Works great
Reviewed in the United States on February 15, 2026 by B.D.
    • Easy installation and slim profile
Size: 1-Pack Style: Standard Detection Pattern Name: PR710
2/21/18 Update - I purchased two of these detectors for bedrooms. The rest of our home has AC powered alarms. Twelve days past the return window, one detector started acting goofy and going off frequently for no reason. The alarm was in a bedroom, so it was obviously the worst possible spot for that issue. I had to take it down in the middle of the night just so my teenage daughter could get some sleep for school. I'll contact the manufacturer for assistance but if you're considering purchasing this alarm, heed the large number of low rating reviews that are based on the new number of unacceptable false alarms. I'm now regretting I didn't do so. Like most people, I tend to think "oh, that probably won't happen to me". Well, it did. Now I have to either order a new type of detector or try to get the faulty one replaced through the manufacturer's warranty. Being forced to replace an item purchased only 42 days ago is very annoying. I'll probably just toss it and buy a Kidde. I have a sealed 10-year battery model Kidde in my bedroom similar to this First Alert and the Kidde has been rock-solid for well over a year with zero false alarms. Original review follows I purchased two of these for rooms without AC wired detectors. Both installed very easily and functioned fine when tested. The slim profile helps keep them from sticking out or distracting from the appearance of the room. The alarm is loud but not as loud as our wired detectors or even some other battery operated detectors I've tried. It has a test button but no hush button. It is definitely loud enough to wake and alert if activated. I like the sealed 10-year battery and the fact that it doesn't require frequent changing like battery operated detectors. However, I make sure to test it frequently and not take for granted it will automatically last ten years. ... show more
Reviewed in the United States on January 16, 2018 by SNS
    • Yes! Get them
Size: 1-Pack Style: Precision Detection Pattern Name: SM210
Easy to install. These are sensitive, and will detect the slightest danger of smoke. I am impressed with the quality, and how well it works! 10 year sealed battery, and it's durable.
Reviewed in the United States on December 12, 2025 by Moody South
    • Alarm malfunctioned after a year, First Alert is sending replacements
Size: 1-Pack Style: Precision Detection Pattern Name: SM210
I've had these smoke detectors in my home for about a year now, and two of them started to malfunction. They started alarming (NOT chirping), in the middle of the night. One of them alarmed a few times and stopped after I took it down. The other alarmed every couple of hours until I took it down. The following night, it started to alarm again, but it was constant. I tried to silence, reset, and clean the detector, nothing would turn it off so I eventually deactivated it before I went insane. I called First Alert's product support to let them know what was happening, and they are sending new units to my house. I am incredibly satisfied with their customer service, but wish I didn't have to deal with the malfunctioning alarms in the first place. ... show more
Reviewed in the United States on June 17, 2025 by Stephanie Edwards Latchu
    • Good
Size: 1-Pack Style: Precision Detection Pattern Name: SM210
Relatively low profile and unobtrusive. Light is much less annoying than others.
Reviewed in the United States on February 3, 2026 by Amazon Customer
    • 10-year sealed battery is a game-changer for me.
Size: 1-Pack Style: Precision Detection Pattern Name: SM210
This does work with a loud alarm if in smoke. I am thrilled that I can now buy my First Alert alarm with a 10-year sealed battery. Convenience is key to keeping safe.
Reviewed in the United States on January 18, 2026 by retired teacher
    • No worries for 10 years.
Size: 1-Pack Style: Precision Detection Pattern Name: SM210
Good replacement with a 10 year battery.
Reviewed in the United States on January 26, 2026 by Leonard S.

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