First Alert SMI100, Battery-Operated Smoke Alarm, 2-Pack
4.5 | 22,650 ratings
Price: 29.99
Last update: 12-22-2025
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
- 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 it’s time to replace the alarm
- Test/silence button for efficient testing to ensure alarm is working properly
Product information
Features & Specs
| Power Source | Battery Powered |
|---|---|
| Alarm | Smoke |
| Sensor Type | Ionization |
Style
| Product Style | Precision Detection |
|---|---|
| Color | White |
Measurements
| Item Weight | 0.6 Pounds |
|---|
Warranty & Support
Amazon.com Return Policy:Amazon.com Voluntary 30-Day Return Guarantee:You can return many items you have purchased within 30 days following delivery of the item to you. Our Voluntary 30-Day Return Guarantee does not affect your legal right of withdrawal in any way. You can find out more about the exceptions and conditionshere.
Manufacturer’s warranty can be requested from customer service.Click hereto make a request to customer service.
Feedback
First Alert SMI100, Battery-Operated Smoke Alarm, 2-Pack
Share:https://www.amazon.com/dp/B0CJLN45JZ
Found a lower price? Let us know. Although we can't match every price reported, we'll use your feedback to ensure that our prices remain competitive.
Where did you see a lower price?
Fields with an asterisk*are required
Pleasesign into provide feedback.
Item details
| Brand | First Alert |
|---|---|
| Model Number | SMI100 |
| Manufacturer | Resideo |
| UPC | 029054022400 |
| Customer Reviews | 4.54.5 out of 5 stars(22,650) 4.5 out of 5 stars |
| Best Sellers Rank |
|
| ASIN | B0CJLN45JZ |
| Item Type Name | Smoke Alarm |
| Built-In Media | 9V Alkaline Battery |
| Item Height | 1.9 inches |
| Unit Count | 2.0 Count |
Top reviews from the United States
- Tiffany KingGreat, Long-Lasting Smoke Alarm Brand!I bought this as a replacement for a 10-year old First Alert Smoke alarm in my son's room. I was hoping it would just screw in to the existing bezel that comes with it but it is a lot different. So be prepared to remove and install the new one. I was able to use the same screw holes as the old one though, so it was nice to not have to make new holes in the wall. Seems to be a good quality, I had to jiggle the battery around to get it to engage. It is battery-operated so there is no wiring to mess around with and makes it easier to install. The alarm sound is loud (as it should be) and it doesn't chirp randomly like my other one started doing (even after the battery was changed). This is a great brand and my last one lasted over 10 years and I still have other First Alert Smoke Alarms in the house that I test and are still going strong after 10 years.
- Brianna GuthGreat valueBought multiple for house. Alarm functions well and battery lasts long. Good quality.
- Reviewer 03Easy to install & works greatSo easy to install! Works a little too well sometimes, easy to turn on and off, chirps clearly and hasn’t had detection issues. Haven’t had any smoke to detect but he goes off if things get hot enough! Directions were very clear and I installed it in under 5 mins.
- Amazon UserCheap alarm for peace of mind, easy to replace if there's a problemBought this alarm to replace our "we changed the batteries last month, why is it intermittently beeping" alarm. This one is so sensitive that it goes off when the oven's on BROIL.
The good news is that it's really easy to turn off for a false alarm; just press the button on the alarm's face.
It's easy to install and comes with instructions and hardware. If you are purchasing a replacement, you don't even need to install hardware. You can easily twist this on to an existing plate (again, if it's a replacement - worked for us, your mileage may vary). We purchased new smoke alarms <5 years ago, have replaced the batteries several times, and are now replacing the alarms themselves.
PRODUCT CLAIMS
- ionization sensor for smoke detection - I'm not sure about this, but we have one outside of the bathroom, and it does go off during particularly steamy showers
- battery operated alarm unit monitors during power failure - We've had no issues (and, if anything, more peace of mind) during times without power
- easy to install - VERY easy. You need a drill or screwdriver. That's it.
- single test/silence button - Easy to find, easy to turn off, easy to test. Battery is easy to check and change with the side battery door.
If you need a smoke alarm at a good value, and don't mind replacing it a few years down the line, this is the product for you. For this price, it's easy to get one for each bedroom and floor of your home (as they recommend). Keep a few extra 9V batteries handy in case you need to replace one at an inconvenient time. - kthompsoGood, reliable, and affordable. Better than AC detectors.I replaced all of my hard-wired smoke alarms with these battery-operated alarms. They work great. No more chirps that are difficult to track. I put a reminder on my cell calendar to change all the batteries every year and I've had no issues. The alarm is loud and easy to test while standing on the floor with a broom handle.
- Walter c ElliottEveryone should haveWorks well. Had a little smoke while cooking and set off alarm.
- terrySmall low profile; works, much nicer than larger unitsPetite little cuties that were the easiest install of any smoke detector ever. I had to replace all 6 in my house (they were 20 years old). The font in the instruction guide was micro, so I used a magnifying glass and the readability was fine. The are compatible with any room because their tiny size and profile keeps them un noticable. I tested each one before installing and they all function. The box came with all 6 smokes, all the needed screws, and 2 anchors of each smoke incase you need them. Very pleased
- DTVery sensitive, I trust it. Easy to set up. Not Made in CHINA.Made in Mexico, not China. Very sensitive. I opened toaster oven in kitchen, no visible smoke, and it goes off.
So it will go off easily. But that's a good thing.