FIRST ALERTBRK 9120B6CP Hardwired Smoke Alarm with Backup Battery, 6-Pack & BRK SC9120B Hardwired Smoke and Carbon Monoxide (CO) Detector with Battery Backup, 1 Pack

Installation was straightforward, "network" response in testing to set all off at the same time has about a two second delay, but worked great!

Did you know smoke detectors expire every 10 years? I didn't until every alarm in my house started going off nonstop. Thankfully, my neighbor is a fireman and he let me know the issue! I bought this pack and installed them all myself while 7 months pregnant, so basically it's simple! Thrilled with my purchase for sure.

It was fairly easy to replace my old units that were over 23 years old with these. There was no need to do/redo any electrical wiring, but I did turn off the circuit, as a precaution.

Works well and a good price.

This smoke detector will randomly beep when it has reached EOL which I think is about 7 years. The beep is crazy loud and annoying. I have had to replace two in the last 7 years and both did the crazy loud beep thing. Once they reach EOL changing batteries will not stop the beep. I called the company and they said you have to replace them once they start doing the beep thing. Both the detectors I replaced were the ones that had both smoke and monoxide detecting. My detectors that are smoke only, are the same age and have not had to be replaced as of yet. They are 8 years old.

Just easy replacements for the existing set in the house. Nothing else must to say they work they're fine.

Lightweight and very comfortable.

5/6 detectors do not work.