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Extended holiday returns
FREE refund/replacement until Jan 31, 2027 Learn more
FREE refund/replacement until Jan 31, 2027 Learn more
This item's return window has been extended for the holiday season: FREE refund/replacement until Jan 31, 2027
To qualify for a full refund, items must be returned in their original, unused condition. If an item is returned in a used, damaged, or materially different state, you may be granted a partial refund.
To initiate a return, please visit our Returns Center.
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Availability:
In Stock.
Arrives
Wednesday, Nov 18
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At a glance
- Condition
- New
- Number of Items
- 1
- Model
- SMI105-AC
- Dimensions
- 5.6"D x 5.6"W x 2"H
- Weight
- 11.2 oz
- Color
- White
- Style
- Precision Detection
Features 6
- 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 battery backup provides continuous protection during power outages
- Through early warning interconnect, when one alarm sounds, all compatible* alarms will sound
- Alarm indicator visually identifies the unit that initiated the alarm
- End-of-life warning lets you know when its time to replace the alarm
- The date shown on the product is the Manufacture Date, which identifies when the product was produced
Description
The First Alert SMI105-AC Interconnect Hardwire Smoke Alarm with 10-Year Battery Backup uses First Alert's Precision Detection advanced sensing technology and meets new industry standards. Interconnect multiple alarms together to help provide an early warning throughout your whole home and have peace of mind knowing the 10-year battery backup provides continuous protection in the event of a power outage.
Specs 20
| Brand | First Alert |
|---|---|
| Style | Precision Detection |
| Power Source | Corded Electric |
| Color | White |
| Product Dimensions | 5.6"D x 5.6"W x 2"H |
| Item Weight | 11.2 ounces |
| Alarm | Smoke |
| Operating Humidity | 10-95% RH |
| Sensor Type | Ionization |
| Unit Count | 1 Count |
| Model Number | SMI105-AC |
| Number of Items | 1 |
| Item Highlight | SMI105-AC |
| Manufacturer | Resideo |
| UPC | 029054022615 |
| Built-In Media | Easy Adapter Plug |
| Item Type Name | Smoke Alarm |
| Mfr Part Number | SMI105-AC |
| Product Style | Precision Detection |
| Item Dimensions D x W x H | 5.6"D x 5.6"W x 2"H |
No specs match.
Frequently asked questions
If you place your order now, the estimated arrival date for this product is:
Wednesday, Nov 18
Yes, absolutely! This item's return window has been extended for the holiday season: FREE refund/replacement until Jan 31, 2027.
To initiate a return, please visit our Returns Center.
View our full returns policy here.
To initiate a return, please visit our Returns Center.
View our full returns policy here.
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Similar Products
Top Amazon Reviews
Fresh from production
Style: Precision Detection
Pattern Name: SMI105-AC
Size: 3-Pack
I ordered 2 of these 3-pack of First Alert Smoke Alarms in June of 2026 and I was delighted to see that they were manufactured in May of 2026; i.e., they hadn't been sitting at the warehouse for 5 years. The batteries were fresh and ready to go. I removed all the old ones and installed all of these in my house. They all worked when tested. ...Let's hope I never need them.
...
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Reviewed in the United States on July 3, 2026 by Booktroll
Good Value, Good Detector
Style: Precision Detection
Pattern Name: SMI105-AC
Size: 3-Pack
Very easy to install. I bought two 3 packs, I needed 5. Installed the 6th in a neighbor's condo that only needed one. I got rid of all my old 9v battery backup detectors. 10 year battery is Great! The Fire Inspector came, tested it, and gave it a Thumbs Up. I'm good for 10 years.
Reviewed in the United States on July 2, 2026 by Michael M
Seems to be ok for now
Style: Precision Detection
Pattern Name: SMI105-AC
Size: 3-Pack
Finally replaced my old smoke detectors and good thing I checked. Some were 2005 and some were 2014. Supposed to only be 10 years of use. I know the old ones did work because when I cooked with lots of smoke the detectors went off but using them on borrowed time is not a good policy. Checked all of the ones I ordered and they were manufactured with July 2026 dates. Installed them myself with the existing hardware (same brand came with the house) and no problems. All lit up green and no chirping indicating bad batteries or bad electrical connection. Been about a few weeks and still no problems. Bought the 10 year detectors which are just non-rechargeable lithium batteries that have a shelf life of 10 years and can't be replaced (unless you pry them open and replace them yourself). Not sure if these will last that long with the amount of power outages we have. Otherwise seems to be working fine.
...
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Reviewed in the United States on August 28, 2026 by g
Easy install with my own screws
Style: Precision Detection
Pattern Name: SMI105-AC
Size: 1-Pack
Screws to mount were missing but otherwise I'm very happy with it. Easy install once I found my own screws. Really like the 10 year battery as I am getting to old to climb up on a ladder to change a battery
Reviewed in the United States on June 6, 2026 by Amazon Customer
Get some
Style: Precision Detection
Pattern Name: SMI105-AC
Size: 3-Pack
Our old ones were 22 years old. Guess we got our money’s worth. Ten years is the recommended interval. Worked just fine with our existing wiring (it’s a standard). Ten year battery no replacement needed.
Reviewed in the United States on September 23, 2026 by fixedgear
Quick Replacement, Instant Peace of Mind
Style: Precision Detection
Pattern Name: SMI105-AC
Size: 3-Pack
Quickly replaced my aged-out 10-year-old detectors, fit exactly in the already in place holder. Used the exact same plug system, and so it required no rewiring, and they not only tested perfectly, the interconnect compatibility alarmed all of the exiting working units in my home- as they should! They are loud! They are also a great value with the 10-year battery, so that means I can set it and forget it! Will absolutely purchase again when needed.
...
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Reviewed in the United States on July 6, 2026 by Ryan
Absolute fail of a product.
Style: Precision Detection
Pattern Name: SMI105-AC
Size: 1-Pack
Absolute fail of a product. I guess having a battery that simply fits into the alarm tray and then you slide the tray into the alarm would be too simple. Nope, someone had to over-design this, and now the alarm comes with a battery tray that is LOCKED! but you can't open it. It says refer to instruction on how to do this, but the instructions (that's a very loose term btw) don't specify how to open the damn tray. It just says use a tool to cut the pin...what pin? where is the pin? there is nothing there. So you have an alarm that you cannot activate because the clear tape that you should pull out to activate the battery won't pull out, and the battery tray won't open. I guess its suppose to be a safty device that no one needed, to stop tampering I suppose. But why have the default state it's shipped as locked?????......update: So after having spent a conciderable amount of time online and finding many others tearing their hair out with the same issue, i finally found wher ethe pin is. It's actually hidden. i kid you not. It's under the slabel sticker that covers the entire underneath of the alarm. Loads of tiny information that mostly doesn't concern anyone is printed on this label. and in what's probably the smallest possible font size is a little note telling you to cut a small part of the label away/scrape it off with a knife (because it wont just peel) and underneath the label, hidden away, is a TINY pin. No indication what it is or how to remove it. It's white plastic, so is the entire alarm. It's almost impossible to distinguish it from the alwarm housing. I took a jewelry screw driver I was fortunate enough to have. There is no way to unscrew it, you just have to force it out and hope thats what you are supposed to do.......I nominate this for 'Design fail of the year'
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Reviewed in the United States on May 26, 2025 by Bolan
Nice smoke detector.
Style: Precision Detection
Pattern Name: SMI105-AC
Size: 1-Pack
This smoke detector works as advertised. Installation was easy and straightforward. Don't know if it will last the 10 years, but as of rIght now it seems sturdy and well built. I recommend this product.
Reviewed in the United States on August 1, 2026 by Willy298