First Alert Onelink Safe & Sound - Battery Powered Smart Hardwired Smoke + Carbon Monoxide Alarm and Premium Home Speaker with Amazon Alexa

The reviews on this product are pretty skimpy and only covered setup, so I thought I'd write one up here so that it's clear what the value of this device is. I have 6 of these and have been using them for a few months, so I'm very familiar with them.Here are the benefits in the order that I value them (I'll go into detail below the list):1. They're AirPlay 2 speakers, so you get whole-home audio if you're an Apple iPhone, HomePod, or AppleTV user.2. They have built-in rechargeable batteries, so you'll never have to replace a 9v backup battery again.3. They are HomeKit compatible, so you can monitor and control them from your iPhone's Home app.4. They have a multi-color LED night-light that you can control or even automate via your iPhone's Home app.5. They're trivial to install.6. Oh, yea, they're a smoke & C02 detector.1. AirPlay 2First I'll focus on what I get the most benefit from - these are AirPlay 2 speakers that take advantage of the fact your home has power wired to all of your smoke detector locations, which means every bedroom and most public spaces.Smart smoke detectors are boring, right? Yes, they are. But this is not just a smart smoke detector. It's a key part of an Apple-based-ecosystem whole-home audio solution. If that sounds interesting to you, you'll love these.You can play music to one or all of your Onelink Safe & Sound from your iPhone or from any HomePod or AppleTV. They sync perfectly. So if you always wished you had a whole-home audio system but didn't have pre-wiring in your ceilings, now you do... since every home built after 1986 has AC power wired to every smoke detector.The audio quality is surprisingly good and the devices work great. I have 6 of these in my home which I just in conjunction with some HomePods, and it's super nice to have music fill the home with one verbal request to Siri. (Pro tip: if you tell your HomePod to play music everywhere, it will play on all of your Onelinks.)Even my wife uses them occasionally by playing audiobooks from her iPhone to the Onelinks so that she can listen to her books throughout the home without carrying around her phone.2. BatteriesI don't need to go into this too much--tracking down a beeping smoke detector in the middle of the night is awful. These have built-in rechargeable batteries and you'll never have to get on a ladder to replace a battery again.3. HomeKitThese devices are Apple HomeKit-compatible, which means they appear in the Apple Home app and you can control them with Siri.4. Night LightThe night lights are helpful - they light hallways and stairwells. I use HomeKit's automation feature to change the color and brightness of the lights at different times of the day, so at sunset they glow orange and when I go to sleep the one in my bedroom dims to a very faint red, etc.5. InstallWith a ladder and a screwdriver, you can replace your existing wired smoke detector in about 3 minutes. Considering what you get in 1-4 above, that's pretty awesome. It's kind of genius to take advantage of the AC power in the ceiling to reduce clutter and give you whole home audio for 5-minutes per room?6. Smoke & C02Honestly, I have no idea... I've never had a fire in my house so they've never gone off! It's First Alert so we can assume they're at least as good as the smoke detectors I had before. That's not really why I bought them... if you just want a smoke detector that doesn't do anything else you can get a Nest.7. Stuff I barely use, but works fineI'm an Apple guy, so I don't use the Amazon features very frequently. I do occasionally use the built-in Alexa capability to turn off smart lights, etc. and it works. But I don't use Amazon music, etc. If you prefer Alexa/Amazon Music, I can say that it works - I've tried it and I've used it. But as an Apple person, I typically use them for the AirPlay 2.

I don't even know where to begin - this thing is an utter pile of trash. I, like you, was excited about the idea of this device - it does everything we want, all in one. I'm building a tiny house, and the idea of combining our smoke, CO, and Alexa speaker into one was brilliant. The device has earned 1 star for best intentions. Now - the ugly.The device was easy to install. It has a simple clip that plugs into the ceiling, and you screw it onto a bracket. That's where the first issue started. When you screw the device into the bracket, a small plastic tab is switched, telling the device whether it has been correctly mounted or not. The setup app loves to tell you that there is a mounting issue. After not even a week's use, the mounting issue came back and persisted, prompting my investigation.After removing the device from the ceiling a few times (which trust me, you'll have to do many times after all the false alarms that you won't be able to disable without unplugging the device), this plastic "mounting position" switch became totally useless. It didn't break off - it wore down to absolutely nothing. You can dig into this plastic with your fingernails - it's total trash.So, to try to get this damn thing to work, I super glued the switch in the "correct" mounting position. I screwed it back onto the bracket, and the problem was solved. So I thought...Although the device was now "tricked" into thinking it was mounted correctly, it continued to set off false alarms. Now, you can "disable" the alarm via the app or by pressing the button on the side of the device. But it doesn't ACTUALLY DISABLE the alarm. It simply "snoozes" it for 5 minutes or so. Then it goes off again.Here I am in the middle of the night now, and this f*#@ing thing is going off like a screaming banshee. I hit disable (AKA "Snooze") and sleep for a few more minutes before it flips out again. This goes on and on. I try to unplug it and plug it back in - but there is no way to reset it now, since I've had to glue the SWITCH SHUT to trick the device into working. So, I unglue the switch, factory reset the device again, reglue the switch... thank god - it's back!Until another false alarm goes off and it cannot be disabled still, only snoozed. By this time, I have had enough. I follow instructions on the back of the device to permanently discharge the device, killing the supposed 10 year batteries permanently. Fine. I have to disable it at this point - it was causing a ruckus for the neighbors and my family alike. So, I stab into the back of this $200+ brand new thing, and switch the disable switch.What happens? NOTHING. Even the disable switch DOESN'T WORK. It might take a hammer and chisel to finally disable this pile of trash. I am so disappointed I really can't even find words for it. This device could be awesome - but they need to work out some bugs. I won't even go into all the glitches with Alexa or the headache of trying to manage it from two devices. This thing sucks. Save your money folks. Sorry.