






🔥 Stay ahead of danger with 10 years of smart, connected protection!
The First Alert SMI105-AC is a hardwired smoke alarm featuring Precision Detection technology that minimizes nuisance alerts while providing early fire warnings. It interconnects with compatible alarms for whole-home safety and includes a 10-year battery backup to ensure continuous operation during power outages. With visual alarm indicators and end-of-life warnings, it offers reliable, long-term protection designed for modern homes.











| Brand | First Alert |
| Color | White |
| Item Weight | 0.7 Pounds |
| Power Source | Battery Powered |
| Product Dimensions | 5.6"D x 5.6"W x 2"H |
| Style | Precision Detection |
J**N
Nice units and look great
Easy to install. Make power is off before you begin. Remove old detector but leave the screws annd use those to attach the new one to the electrical box. If you need to use the included adapter go ahead and connect the white to white, black to black and orange to red. Then just connect the adapter to the new detector. Be sure to remove the clear plastic strip to activate the battery. NOTE. You don’t need to connect the orange to red if the detector is not going to be connected to communicate with other detectors.
A**S
Works Great — Once You Actually Install It (According to My Wife, 3 Months Late)
Bought this smoke detector because, you know, fire safety is important… Apparently not important enough for me to install it in under 90 days. But hey — I had other things to do. Like reorganize the garage. Twice. And stare at it in the box on the kitchen counter like it was going to mount itself. Meanwhile, my wife spent three months walking past it like she was in a house made of dry hay and open flames. Every time the oven turned on, I got the look. You know the one — the “If the toaster sparks, we’re done” look. ⸻ 🔥 Smoke Detector Functionality Once I finally summoned the courage (and a step stool), this thing installed easily and worked like a champ. Tested it with the “toast test” and yep — she’s got lungs. Loud enough to wake the neighbors, the pets, and possibly the dead. I feel safer already. So does my marriage. ⸻ 💵 Value for Money Excellent. A small price to pay for not living in a potential fireball and regaining my wife’s trust. Honestly, I should’ve paid more just for the emotional damage I caused by procrastinating. ⸻ 🧰 Quality & Build Solid construction. Doesn’t feel cheap or flimsy. You can tell it’s built to detect danger, not just hang out on the ceiling for decoration. ⸻ 🔄 Ease of Replacement Swapping it in for the old detector was fast and painless. If only me actually doing it had been that easy. Seriously, it took longer to unwrap it than to install it — once I finally picked up a screwdriver. ⸻ 🧯 Final Thoughts: • Yes, it works great. • Yes, it’s loud, reliable, and makes us feel safe. • No, I can’t explain why it took me a whole fiscal quarter to install it. Wife’s happy. House didn’t burn down. Marriage survived. 10/10 would delay installation again (kidding, honey).
A**1
Easy to install. Peace of mind
Easy to install. Working nicely one year later
J**D
so far, so good
I received what I ordered. These have built in batteries with 10 year lifespan, so there is no need to replace batteries every year. I ordered 7 of these and the battery lifespan started within a couple months of my purchase date - I didn't receive anything old. The smoke alarms are all the same and easy to install. They have a third wire to use for networking.
B**E
Replacing existing First Alert alarms
These are to replace current First Alert units that began having false alarms. The existing alarms had new batteries and had dust blown out with canned air. They are 6 years old so we're replacing them with these newer models with 10-year batteries. They were very simple to replace. We'll see how well they hold up.
T**I
These units could be a lifesaver
I installed these new smoke detectors with CO2 detection. They install very easily and I’m happy with their quality.
B**C
Great Value for Great Technology
I have purchased many smoke alarms over many years, especially the earlier ones with batteries that went bad and needed to be replaced, always chirping in the middle of the night. I never considered buying the alarm with a 10 year battery life. So when the battery alerted me (probably the entire building) that I needed a new alarm I recalled that I could and should go with the 10 year upgrade which was very reasonably priced. Being a senior, partially disabled, and living in Manhattan, hardware and big discount stores are hard to find (especially at 2 AM!) so I remembered, Amazon Prime, next day. I am so grateful to have this option of convenience and availability. It has made life so much simpler.
J**A
Easy install
Easy to install
Trustpilot
2 weeks ago
5 days ago