First Alert 9120B Smoke Detector, Hardwired Alarm with Battery Backup, 3-Pack

Ordered this set to replace all my upstairs smoke detectors! They were pretty much newer versions of what I had, very simple install all function well as well! Great value and great quality from a trusted brand!

Perfect replacement for a smoke detector that wouldn’t stop chirping. Replacement mounting hardware was identical to original, wiring simple, good price.

I recently installed the First Alert SMI100-AC Hardwire Interconnect Smoke Alarm throughout my home, and I’m really impressed with its performance and ease of use. Installation was straightforward. The unit is designed to be hardwired, and it also includes a battery backup, which gives added peace of mind during power outages. It integrates well with other First Alert alarms, so if one goes off, they all do — exactly what I was looking for in an interconnected system. The alarm is loud and clear, which is essential for ensuring everyone in the home is alerted quickly in an emergency. The test and silence buttons work as expected, and the indicator lights are easy to understand (green for power, red for alarm/test). What I particularly appreciate is the build quality. It feels solid and well-made, not flimsy like some other brands I’ve tried in the past. If I had one minor critique, it would be that the instructions could be a bit more detailed for first-time installers. If you have older Wired Smoke Detectors you may need an electrician to connect the new connector if you are not comfortable do that work yourself Overall, this is a reliable and well-built smoke alarm that offers great protection for your home. I highly recommend it!

Easy to install, fades into the ceiling nicely. Quality appears good. I am assuming it works well since test worked well.

It was time to replace my hardwired smoke detectors and while there are tons of brands with fancy features, I want reliability and a proven track record. I am not risking my family's safety on some discount smoke detector so I went with First Alert. I had Kidde smoke detectors previously so I had to replace the base and rewire them but it is a simple process that takes about 10 minutes for each detector from start to finish. They have only been installed a few days but they seem to work well. They include 9v batteries but be sure to check them as well as the date stamped on the back of the detector to make sure you are getting new products. My only complaint about the smoke detector design is the pivoting tray used to hold the battery - 2 of 4 were very difficult to close and the plastic is very rigid and felt like it would snap. The marks for positive/negative can also be a bit hard to see. It is worth mentioning that the green power light is very bright. It doesn't bother me but could be an issue for some. I recommend these detectors though I had a lot of issues ordering from Amazon. They do not sell 4 packs so I ordered a 3 pack and a single detector. I purposely ordered products that were shipped by Amazon but that is not what happened. The single detector was sent immediately from a 3rd party...not Amazon but whatever. It was 2 months old and seemed fine. I was informed the 3 pack of detectors was being sent by some other 3rd party and was delayed a couple of days. So Amazon just decided to use a 3rd party even though I actually paid more to get it shipped by Amazon. Then the delay was a week and it still didn't arrive and tracking showed it hadn't even been shipped. I cancelled the order and placed another making certain it was to be shipped from Amazon. Except it wasn't. Instead, it was shipped by another 3rd party and was delayed again, this time with no definitive delivery date. I had to cancel that order and went to Lowes where I paid more but at least I had them. Thankfully the single detector that was sent initially worked fine. I recommend the smoke detectors but I did not have a good experience ordering through Amazon.

First Alert has always been the go to smoke detector. They are interconnected with a battery backup. Also, easy to install.

Easy replacement for old smoke detectors. Remove old smoke detector (unplug from interconnect / AC power plug), loosen two screws and remove old mounting ring, install new mounting ring and tighten the two previously loosened screws, plug in interconnect / AC power plug on rear of new smoke detector and seat it into the mounting ring - test - done. Simple, took about 10 minutes per device including moving the ladder around in the house. Good price for a great product.

Perfect replacement for malfunctioning smoke detector. Just remove and replace.