I installed this 4 years ago and I love everything about. Install was smooth and easy. It integrates to Alexa/Ring perfectly. I accidentally blew my vape very close to it and it immediately went off. Alarm is extremely loud - loud enough to hear throughout the house. Even so, every Alexa in the house started yelling at me, in case there is a room far enough away that you couldn't hear it. Additionally, I immediately got a phone call from Ring, asking if they should send emergency services. I don't know that I should even voice my annoyance with an event. All Echo devices go to a 10 volume and the alarm itself is LOUD, so in an accidental activation, I found myself frantically screaming 'ALEXA STOP!!!' but could not be heard over the alarm. I struggled for a few seconds to stop the alarm using the button on the actual device. In the meantime, I answer my ringing phone to tell them not to send 911 but they couldn't hear me until I managed to stop the chaos. To end it all, after I told them "There is no fire", they called my secondary contact to confirm. That would be a nice feature if the alarm on the keypad were pressed by a DV victim, but for my smoke alarm going off, it seemed a bit unnecessary. Still, 10/10!!!

I am a big fan of these detectors. They are not overly sensitive and do not trigger to bad cooking in my house. The added benefit of CO detection is awesome and I think should be part of every detector. Z-wave is reliable and does not seem to harm battery life too bad. I really love having the peace of mind these give by integrating them in Home Assistant so I can get a notification when one alarms. That way I know if there's something to worry about either somewhere in my home I can't hear the alarm, or when I am away. Worth the price!

We have been using this for many years. Reliable products and works effectively!

The alarm works as it is supposed to and was easy enough to integrate in home assistant via zwave, and is loud enough for its job. The functionality could be more robust, but i assume most of these are due to being a battery powered unit rather than hardwire: 1. I wanted to be able to link these in home assistant such that when 1 went off, it would cause the rest to go off as well. Sadly this is not possible as the unit does not act as a listening device to conserve battery. 2. For some reason the silence button doesnt seem to work. If the alarm is triggered, i have tried multiple times short and long pressing the silence button, but it just doesnt seem to do anything. I have to slide the battery tray out to turn it off. Not a big deal as the battery tray is easily accesible.

Would buy again

I've had this alarm for about a month, and am very pleased. So much so that I purchased a second two weeks after the first. However, before I get to the rest of my comments, I'd like to say something about the nature of reviewing smart devices in February 2016. Right now there are several smart systems, not really a clear front runner, and the ecosystems are rather young. I've seen a number of devices where there were strong correlations between the review given, and the system used. The device didn't change between the two systems, the systems changed. The hubs were different, with different chipsets, with different firmware, with different software, with different setups in different houses. So, just a word of advice that a negative review with System A doesn't necessarily mean there would be a bad experience with System B. Try to make sure your situation will be similar before valuing the review - and take everything with a grain of salt. With that out of the way, I'd say that this product is designed well. The alarm is loud, and was fairly sensitive to smoke in my testing. When I say "fairly", I would consider that optimal. Very sensitive would be too sensitive, and cause false alarms, and insensitive is useless. I've not been able to test CO2, so no comment there. The first one I purchased has been running about a month, and is down to 92% on the batteries. It is about twenty feet from my SmartThings v2 hub, with only a couple walls in the way. So, I think that is decent battery life. The second one is in line with that battery usage, and is much father away. Pairing was super easy, no problems there. And, one thing I really liked is the rounded-octagon shaped. That made it very easy to screw in or out of the mounting bracket. I'm not sure if this is SmartThings, or the device, or my software revision, but I was unable to clear the alarm through SmartThings. Seems like that can only be done on the device. But, I don't believe I ever saw anyone specifically mention being able to do this - with any system - so perhaps that is not even an option. But, I could see it as a nice touch. I can hit the button to clear the alarm, because I'm taller, but my wife would have to go get something to step on while it is going off. Having the ability to clear it from SmartThings would be nice for her. But, it's a smoke alarm, hopefully that shouldn't be a common problem, right?

Easy to install and add to my Ring system.

Set up with ring out of the box in a matter of seconds. Works flawlessly with Ring. My first complaint is having to change batteries every couple of months. May be a tad sensitive to a smoldering wood stove for CO but that is probably a good thing. My bigger complaint is disarming Ring when it's alarming does not silence the smoke detector. So if you are not home and get a CO alarm from your wood stove it will drive your pets crazy until you can get home to manually silence it.

To get Zwave CO and smoke detection at this price is pretty good, but I was startled when it went off after one of my kids got out of the shower and the steam triggered the smoke alarm. Is don't recall ever owning a smoke detector that had false positives on steam. Don't mount this outside of a bathroom or where steam can hit it... unless you need a steam detector for some reason ¯\_(ツ)_/¯ Jury is still out on any false negatives.

So, what if the package is dented. The product is brand new and I got it in Amazon warehouse as a like new item at 25% of the price.