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First Alert SMI100-AC, 9120B Replacement Hardwire Interconnect Smoke Alarm with Battery Backup, 1-Pack

4.6 (8) Write Review
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$20.99

$ 9 .99 $9.99

In Stock

1.:Precision Detection


2.Size:1-pack


3.:Smi100-ac


About this item

  • 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.
  • Through early warning interconnect, when one alarm sounds, all compatible alarms will sound
  • Battery backup provides continuous protection during power outages
  • Alarm indicator visually identifies the unit that initiated the alarm
  • Quick Connect Plug included allows for easy installation with no need to rewire


The First Alert SMI100-AC Hardwire Interconnect Smoke Alarm with Battery Backup meets new industry standards utilizing First Alert's Precision Detection advance sensing technology. This hardwire smoke alarm is easy to install and replace existing alarms with no need to rewire. Plus interconnect compatible alarms to create a whole home alarm system to help provide an early warning.


Roy
August 3, 2025
Excellent replacement for original smoke detectors. Easy to install with clear instructions. Great price and LED indicators are a plus to see that units are working. A definite recommend
Robert A. Finkle
June 17, 2025
Easy to install. Batteries are not as easy to change due to door lock system but since its is one time a year it is not an issue.
Customer
June 3, 2025
Easy to replace, and came as described.
Grammy2012
February 15, 2025
The installation of these smoke detectors was straight forward. Each one worked just fine. I would buy them again. My tiny problem was they didn’t come with screws. It’s a new build so no existing mounts. Wish I would have known to save a trip to a store when we live 30 miles from a store out in the country. But all in all a good product at a good price.
Carmen Seal
February 9, 2025
This was exactly the same as the old ones I replaced which I had for 17 years. Plugged right in.
Kyle K.
January 28, 2025
We had a bunch of old, expired hard-wired smoke detectors in our house. These were perfect replacements for them, and they all worked well together. I didn't have any issues with them communicating with the others whenever you tested them. No complaints and they test out as expected.
Kharmangia
January 13, 2025
Arrived in great shape, early and they were easy to install.
Cee Dee
November 20, 2024
Easy installation-- work reliably. Nice to have these updated smoke alarms in the entire house.