First Alert SMI100 Battery-Operated Smoke Alarm
First Alert SMI100 Battery-Operated Smoke Alarm
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First Alert SMI100 Battery-Operated Smoke Alarm

222 ratings

Key item features

  • Advanced Sensing: Equipped with Precision Detection advanced-sensing technology, this alarm reduces nuisance alarms and accurately detects smoke from synthetic materials that burn hotter and faster, allowing for more escape time.
  • Convenient Battery Power: Battery-operated design allows for easy installation without electrical rewiring and ensures continued operation during power outages, offering versatile placement options.
  • User-Friendly Controls: Features a single, convenient test/silence button for simple operation and a front-access battery door that facilitates easy and quick battery replacement.
  • Loud Audible Warning: Produces a loud alarm sound level of 85 dB at 10 feet, providing a clear and urgent warning to help occupants safely evacuate.
  • Complete Setup Kit: Comes with essential accessories, including a mounting bracket, installation screws, and a 9-volt battery, for immediate and straightforward setup.
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Customer ratings & reviews

4.6 out of 5 stars
stars
222 ratings28 reviews
How item rating is calculated
  1. 5 stars81% (180)
  2. 4 stars9% (20)
  3. 3 stars2% (5)
  4. 2 stars3% (6)
  5. 1 star5% (11)

Reviews summary

Pros

  • : Requires minimal effort and is easy to complete.
  • : Offers good quality at a lower cost.
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Showing 1-3 of 28 reviews

Aug 1, 2026
Reviewer name: SimonMM
Top Reviewer
5 out of 5 stars
5 out of 5 stars review

Verified Purchase

Simple Upgrade with Serious Peace of Mind

I definitely needed to upgrade my old smoke alarm and this one made the process painless. The instructions were clear, setup was quick and everything worked exactly as it should. There's a little blinking green light to let you know that it's working. It also comes with a battery pre-installed. Just remove the plastic tab and you are ready to go. It is not the most exciting purchase in the world, but knowing it is installed and doing its job is worth every penny. Simple, dependable and easy to recommend. Get one and stay safe!

Helpful?7L1FD97VXAGY17599704914
Jul 20, 2026
Reviewer name: Mack
Top Reviewer
5 out of 5 stars
5 out of 5 stars review

Verified Purchase

Good purchase- working well.

Good smoke detectors working well - good replacement for the smoke detectors that kept going off in the middle of the night! A little hard to set up but finally figured it out and happy with them, Will order two more!

Helpful?7L1FD97VXAGY17599704914
Aug 16, 2026
Reviewer name: anonymous
Top Reviewer
5 out of 5 stars
5 out of 5 stars review

Verified Purchase

easy installation

easy to install it.

Helpful?7L1FD97VXAGY17599704914
Current price is $16.99$28.80/ea
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