First Alert

First Alert SMCO210 10-Year Sealed Battery Combination Smoke Carbon Monoxide Alarm with Slim Profile Design 1-Pack

122+ bought in the past month

$39.40$59.99

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.
  • Provides reliable 2-in-1 protection against both smoke and carbon monoxide in an easy to install alarm
  • 10-Year sealed battery eliminates battery replacements and low battery chirps for the life of the alarm
  • End-of-life warning lets you know when it’s time to replace the alarm
  • Slim profile design is half the depth of a standard alarm
$39.40
Was $59.99Save $20.59

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Product details

BrandFirst Alert
StylePrecision Detection
Power SourceBattery Powered
ColorWhite
Product Dimensions5.67"D x 5.67"W x 1"H
AlarmCombination Alarm
Operating Humidity10-95% RH
Sensor TypePhotoelectric
MaterialPlastic
Number of Items1

Technical specifications

brandFirst Alert
stylePrecision Detection
power_sourceBattery Powered
colorWhite
product_dimensions5.67"D x 5.67"W x 1"H
alarmCombination Alarm
operating_humidity10-95% RH
sensor_typePhotoelectric
materialPlastic
number_of_items1
manufacturerResideo
upc029054022233
part_numberSMCO210
item_weight6.4 ounces
item_model_numberSMCO210
batteries1 Product Specific batteries required. (included)
sizeOne
patternSMCO210
item_package_quantity1
batteries_includedYes
batteries_requiredYes
battery_cell_typeLithium
warranty_descriptionWarranty
best_sellers_rank#677 in Tools & Home Improvement ( See Top 100 in Tools & Home Improvement ) #3 in Smoke & Carbon Monoxide Alarms
date_first_availableSeptember 22, 2023

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Customer reviews

4.27,483 ratings

Customers say

Customers report mixed experiences with the smoke and carbon monoxide alarm's functionality, with some saying it works great while others mention it keeps going off for no reason.

★★★★★

Best and Easiest Smoke & Carbon Monoxide Detectors to Install!

StevenOctober 21, 2025

These are by far the easiest smoke and carbon monoxide detectors I’ve ever installed. The 10-year battery is a big plus—no more worrying about changing batteries every year! All you have to do is screw the holder to the wall, place the unit on, and give it a quick turn—that’s it. Simple, fast, and reliable. I’ve tried other brands, but these are definitely the best and easiest to install. Read more

★★★★★

Know what you want and how to install it

Geraldine PurdyDecember 30, 2025

Easy to install and put up Read more

★☆☆☆☆

Complete garbage

Brittany BNovember 2, 2025

If I could give these no stars I would. I purchased 2 of these in Feb to replace some old wired smoke detectors. Install was easy. The trouble came in Sept when one of them started to malfunction and give an alarm all the time when there was no smoke or heavy fumes. Nothing. Also it was not a CO alarm but a smoke. At all hours of the day and night. I finally got so sick of it that I pulled it off the ceiling and wrapped it in a blanket as my poor dog was shaking violently every time it went off. Put it back up a week later. Same problem. So I tossed it. Now here we are in Nov and the other one I bough is doing the same thing. Going off for no reason. Even wrapped in a blanket it was still going off. So I put it out on the porch. With fresh air and everything. And it continued to go off sitting outside intermittently for 2 more days before it too went in the trash. We are of course outside the return window. So I spent $80 to not have any smoke detectors in the house and will have to shell out more money again to buy another brand. These werent old. Both had been up less then 9 months when they malfunctioned. Dont waste your money on these unless you like your pets being traumatized at 2am when the thing randomly goes off for no reason and wont stop. Read more

★★★★★

Big round

DesiDecember 20, 2025

Nice a big just what I was looking for also has a 10 year battery sealed in, after that replace. Sleek design thin Read more

★★★★☆

one year later

LonfuNovember 7, 2025

after one year, almost to the day, it started chirping 3 times which indicates a bad unit. So, blew it out with my air compressor and the chirping seems to have stopped. waiting to see what happens. Read more

★★★★★

Great smoke and co combo

CustomerJanuary 2, 2026

Must have! Read more

★★★★★

Easy to Install - good quality.

Katherine HDecember 2, 2025

Easy to install- seems like good quality - is not chirping at me. Basically so far doing everything you want in a smoke alarm Read more

★★★★★

great deal

mark dillonJanuary 4, 2026

good deal good price Read more

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