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First Alert

First Alert SMCO100 Battery-Operated Combination Smoke & Carbon Monoxide Alarm - 3 Pack

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Availability: In Stock.
Fulfilled by Amazon
Arrives Feb 6 – Feb 12
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Size: 3-Pack


Style: Precision Detection


Pattern Name: SMCO100


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
  • Provides reliable 2-in-1 protection against both smoke and carbon monoxide
  • Battery-operated alarm allows for easy installation and maintenance
  • Test/silence button for efficient testing to ensure alarm is working properly
  • End-of-life warning lets you know when its time to replace the alarm

Description

The First Alert SMCO100 Battery-Operated Combination Smoke & Carbon Monoxide Alarm is equipped with First Alert's Precision Detection advanced sensing technology and meets new industry standards. This 2-in-1 smoke and carbon monoxide alarm provides reliable protection against both threats and is easy to install and maintain.

Brand: First Alert


Style: Precision Detection


Power Source: Battery Powered


Color: White


Item Weight: 1.55 Pounds


Alarm: Smoke, CO


Sensor Type: Photoelectric


Number of Items: 3


Manufacturer: Resideo


UPC:


Brand: ‎First Alert


Style: ‎Precision Detection


Power Source: ‎Battery Powered


Color: ‎White


Item Weight: ‎1.55 Pounds


Alarm: ‎Smoke, CO


Sensor Type: ‎Photoelectric


Number of Items: ‎3


Manufacturer: ‎Resideo


UPC: ‎029054022080


Part Number: ‎SMCO100


Item Weight: ‎1.55 pounds


Product Dimensions: ‎21.5 x 7.5 x 3.5 inches


Item model number: ‎SMCO100


Batteries: ‎2 AA batteries required. (included)


Size: ‎3-Pack


Pattern: ‎SMCO100


Item Package Quantity: ‎1


Included Components: ‎AA Batteries


Batteries Included?: ‎Yes


Batteries Required?: ‎Yes


Battery Cell Type: ‎Alkaline


Date First Available: October 26, 2023


Frequently asked questions

If you place your order now, the estimated arrival date for this product is: Feb 6 – Feb 12

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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Top Amazon Reviews

    • Buy
Size: 1-Pack Style: Standard Detection Pattern Name: SCO5CN
Excellent alarm. It was easy to install, the alerts are loud and clear, and I appreciate having both smoke and carbon monoxide detection in one unit. It feels reliable and well-made, giving some extra peace of mind. Definitely worth the purchase
Reviewed in the United States on November 17, 2025 by Aaron
    • Can’t go wrong with first alert. Piece of mind.
Size: 3-Pack Style: Precision Detection Pattern Name: SMCO100
A member of our family had a close call with some Co2 recently. This prompted me to get six of these first alert combo detectors. Installation is very straightforward. I now have one in every bedroom and the hallway and the kitchen. The fact that they are battery operated is a big plus. No wiring no electric electricians just two screws and you are done. I know that first alert has a stellar reputation for safety and Quality. I have already read some of the reviews of the Great customer service and warranty provide provided as well. I just installed them so I can’t give you long-term reviews, however so far so good. ... show more
Reviewed in the United States on January 4, 2026 by David McKean
    • Best safety device
Size: 3-Pack Style: Precision Detection Pattern Name: SMCO100
Work really well, just got the FMO
Reviewed in the United States on January 6, 2026 by kashif iqbal
    • Good smoke alarm, great warranty!
Size: 1-Pack Style: Standard Detection Pattern Name: SCO5CN
Good smoke/CO detector, malfunctioned after a couple years. I called the company and given their generous warranty policy, they replaced it with the new model for free, just had to pay a few dollars for shipping.
Reviewed in the United States on June 23, 2025 by sol lazarus
    • Easy to install
Size: 1-Pack Style: Precision Detection Pattern Name: SMCO100
Easy to install as used same base as ones I had. The ones I am replacing were over 10 years old and was working fine. Very easy to replace the batteries(2 AA).
Reviewed in the United States on December 31, 2025 by Wayne Mitchell
    • So far, so good!
Size: 1-Pack Style: Standard Detection Pattern Name: SCO5CN
I had a $120 Google Nest Protect previously and it malfunctioned and I believe requires a good wifi connection to really work properly. I wanted something simple and reliable so switched to the this First Protect. So far so good. No false alarms yet and installation was straightforward. They even included drywall anchors, something that was not even included with the Nest Protect. Just drill a 3/16 hole and then lightly hammer the drywall anchors in, then screw the mounting bracket in to the anchors using a phillips screwdriver. You can also rotate the First Alert in it's mounting bracket so that the words line up exactly how you like them. No one likes a smoke detector mounted on the wall with the lettering skewed or upside down. You do not have to screw the unit on the mount all the way in order for it to be secure. The features are simple and to the point, just write down in your smartphone or wherever what the different beeps mean because you will probably forget later on. There are only a few different beep sequences so it's not overly complicated but you will want to know for example when it's telling you the battery needs replacement vs. when it's at the end of it's life cycle. This is an inexpensive, simple and relatively attractive unit, although I really wish smoke detector companies would put more effort in to beautiful designs. That's one of the things I like better about the Nest Protect. ... show more
Reviewed in the United States on October 22, 2020 by Mediahound 🎧
    • Essential Safety Solution: First Alert Powered Alarm SCO5CN
Size: 1-Pack Style: Standard Detection Pattern Name: SCO5CN
⭐⭐⭐⭐⭐ The First Alert Powered Alarm SCO5CN has become an integral part of my home's safety system, providing reliable protection against both smoke and carbon monoxide. Here's why I give it a solid 5-star rating: Dual Protection: This combination smoke and carbon monoxide detector offers peace of mind by safeguarding my family and home against two common household hazards. With one device, I have comprehensive protection against both smoke from fires and carbon monoxide leaks. Reliable Performance: First Alert is a trusted name in home safety, and the SCO5CN lives up to the brand's reputation for reliability. It detects smoke and carbon monoxide quickly and accurately, emitting loud alarms to alert occupants in case of an emergency. Battery Operated: The battery-operated design ensures continuous protection even during power outages. I appreciate the added reliability and convenience of not having to worry about the detector losing power during emergencies. Easy Installation: Installing the SCO5CN is a breeze. With no wiring required, I was able to mount it in minutes using the included mounting bracket and screws. The simple setup process means I can quickly and easily enhance the safety of my home without any hassle. Sleek Design: The sleek, white design of the SCO5CN blends seamlessly with my home decor. Its low-profile design and compact size make it unobtrusive while still providing essential protection. In conclusion, the First Alert Powered Alarm SCO5CN is an essential safety device for any home. With its dual protection against smoke and carbon monoxide, reliable performance, battery-operated design, easy installation, and sleek appearance, it offers everything I need to keep my family and home safe. Highly recommended! 🏠🔥🚨 ... show more
Reviewed in the United States on February 10, 2024 by Eric
    • Battery slot is well hidden
Size: 1-Pack Style: Standard Detection Pattern Name: SCO5CN
Nvm. I thought it was battery-less, but I just found the slot on the side for 2 AA batteries. Works like a charm now! Hmm…. My 10-year alarm went out after 1.5 years. Not sure if I got a dud or if this is a known pattern.
Reviewed in the United States on October 8, 2025 by Amazon Customer

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