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First Alert

First Alert Battery Smoke Alarm

  • Based on 5,891 reviews
Condition: New
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Availability: In Stock.
Fulfilled by Amazon
Arrives Sunday, Oct 4
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Size: 2-Pack


Style: Precision Detection


Pattern Name: SMI100


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
  • Battery-operated alarm allows for easy installation and maintenance
  • Front access battery compartment makes for easy battery replacements
  • 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 SMI100 Battery-Operated Smoke Alarm is equipped with First Alert's Precision Detection advanced sensing technology and meets new industry standards. This battery-operated smoke alarm is easy to install and the front access battery compartment makes for easy battery replacements.

Brand: First Alert


Style: Precision Detection


Power Source: Battery Powered


Color: White


Product Dimensions: 5.6"D x 5.6"W x 1.9"H


Item Weight: 9.6 ounces


Alarm: Smoke


Sensor Type: Ionization


Unit Count: 2 Count


Number of Items: 2


Brand: First Alert


Model Number: SMI100


Unit Count: 2 Count


Number of Items: 2


Item Highlight: SMI100


Manufacturer: Resideo


UPC: 029054022400


Built-In Media: 9V Alkaline Battery


Item Type Name: Smoke Alarm


Mfr Part Number: SMI100


Power Source: Battery Powered


Alarm: Smoke


Sensor Type: Ionization


Product Style: Precision Detection


Color: White


Item Dimensions D x W x H: 5.6"D x 5.6"W x 1.9"H


Item Weight: 9.6 ounces


Frequently asked questions

If you place your order now, the estimated arrival date for this product is: Sunday, Oct 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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Leasing options through Acima may also be available during checkout.

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Similar Products

Top Amazon Reviews

    • Simple to Install & Gives Peace of Mind
Size: 2-Pack Style: Precision Detection Pattern Name: SMI100
This smoke alarm was quick and easy to install, and it provides exactly what I was looking for-reliable protection and peace of mind. The instructions were clear, and it was up and running in just a few minutes. The alarm has a clean, low-profile design that blends in nicely with the ceiling. I also like that it's battery operated, so it continues working even if the power goes out. The test button is easy to access, and the alarm is loud enough to be heard throughout the house, which is exactly what you want in an emergency. If you're replacing an old smoke detector or adding extra protection to your home, this is a dependable, easy-to-install option from a trusted brand. Highly recommend! ... show more
Reviewed in the United States on July 26, 2026 by Rachel
    • smoke alarm
Size: 1-Pack Style: Precision Detection Pattern Name: SMI100
This smoke alarm was just what I needed. It work's great in my RV, fit's perfect, very easy to install, the alarm was load so people can hear it. Price was good for this product
Reviewed in the United States on September 7, 2026 by connie k
    • Simple and easy to install
Size: 1-Pack Style: Precision Detection Pattern Name: SMI100
Basic smoke alarm that does exactly what I needed. It was easy to install, the battery setup is simple, and the test button worked like it should. Good inexpensive option for adding another smoke detector around the house.
Reviewed in the United States on August 21, 2026 by Matthew
    • Great smoke detector
Size: 1-Pack Style: Precision Detection Pattern Name: SMI100
Great brand of smoke detectors. So far they have worked great, but we haven’t had a fire to know exactly how well they work. Thank goodness. Easy to install. Nice compact size.
Reviewed in the United States on September 12, 2026 by Tammy H
    • Great
Size: 1-Pack Style: Precision Detection Pattern Name: SMI100
Love that they come complete and ready to go with the battery installed
Reviewed in the United States on August 22, 2026 by ginger
    • Very pleased with purchase.
Size: 3-Pack Style: Precision Detection Pattern Name: SMI100
Very pleased with this purchase. Packaging was great. Bought this as used and they were in original condition. Batteries were new so nothing had been used or previously installed. I had purchased a First Alert before for my camper from Camping World. It came with a Duracell battery. These did not. I opted for a yeary battery change vs. the 10 year internal battery. I had the 10 year (not First Alert), and they only lasted 4-5 years. ... show more
Reviewed in the United States on June 27, 2026 by Rondmc
    • Reliable product, dependable technology with few false alarms. Easy to install.
Size: 2-Pack Style: Precision Detection Pattern Name: SMI100
Review Image by Whoknowes
Review Image by Whoknowes
Review Image by Whoknowes
Ordered as replacements for a rental property. Arrived as expected based off of the add, installed with the included hardware, the detector fit into the bracket easily. Based on previous version of the detector these have a high level of reliability and with new technology, false alarms from cooking are a thing of the past. The alarm produces a loud alarm that will alert anyone in the house of smoke. Have used this brand and versions of this alarm for years in rental property with no problems and few false alarms. Would order again. ... show more
Reviewed in the United States on August 23, 2026 by Whoknowes
    • Easy and affordable peace of mind
Size: 1-Pack Style: Precision Detection Pattern Name: SMI100
I purchased this smoke alarm to replace one that was very old and needed to go! This one was affordable it arrived quickly and was simple to remove the plastic barrier so the battery would work and then even easier to install on the wall and now I have peace of mind that if something crazy happens at my house this smoke alarm will alert me. I highly recommend this product. ... show more
Reviewed in the United States on August 12, 2026 by Susan Landers Kolb

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