KiddeSmoke & Carbon Monoxide Detector, Hardwired Interconnect, Combination Smoke & CO Alarm with Battery Backup, Voice Alerts, Contractor 6 Pack

These last for ten years. Our old ones started going out. They beep twice every 30 seconds. The dogs were terrified. So we took out the ones that died, found the replacement number on the back, and ordered new ones. Since our wiring was still in place from the old detectors, this was super simple and easy to do. Even better, they were originally going to take almost a month to arrive. Luckily they came in about two weeks. I was also able to order in a quantity of six, which was what I needed.

I used these to replace 12 year old Kidde models because they started having too many false positives. The wiring harnesses fit seamlessly and the mounting brackets were very easy to swap out. The voice and warning beeps are very loud and one unit triggers the rest throughout the house (using the test button and all wired units).

I replaced six hard-wired smoke detectors with these combo smoke/carbon monoxide units. I specifically picked Kidde so that the wiring connection would be the same, thus eliminating the need to mess with the wires in the ceiling. Made things very easy.Warning: Be aware that half the alarms went through a self test once I pulled the tab on the battery. (Every test sets off every alarm in the system, and it is loud!)Suggestion for bifocal or progressive lens wearers: Grab your computer glasses; you're going to be right up top with the ceiling and the near-vision lens help prevent craning your neck.Final comment: I thought that carbon monoxide testers need to be relatively close to the floor, so I have kept the two detectors that were already installed in place. Just me.

Replaced my out dated units (10 years old) with no issues. Direct replacement and came with backup batteries.

I have 12 hardwired smoke detectors in my house, because of the state of Massachusetts requirements. Uggh. So I hate the idea of trying to diagnose which unit has a problem when all 12 are going off bursting my eardrums all over the house. I selected this unit for the voice notification, which should come in handy to diagnose false alarms and weak batteries. So far, so good.However, my 1 star rating is because of something I read in the manual - basically, after these expire in 10years, they will start chirping every 30 seconds, and since they're hardwired there's no way to silence them without pulling them off the ceiling and removing the batteries. So 10 years from now, in the middle of the night when these things start going off, and it's a few days before I can order more to get some sleep, I'll end up having to get a ladder and rip all 12 of these things off the ceiling, and then having no smoke alarm coverage until I can figure out which one I want to buy and wait to get them. I don't know who at Kidde thought this was a good idea, probably the lawyer and not the engineer... But I know I will hate these and this company in 10 years, so I'm writing that review now.

Battery replacement is made easy with the easy access via a push-button style compartment. Fits nicely over existing hole and the provided mount is designed very well. Highly recommend.

I purchased 7 of these to replace 20-year old detectors in my home. It took me approximately 1 hour to replace all 7 (including flipping breaker switches, moving the ladder around, etc.) I saw other reviews stating issues with unnecessary chirping (like a low-battery indicator) but I had absolutely no issues with them. They've been operational for about 2 weeks now. Would definitely purchase again.

Bought a 6 pack but only 4 work.