AqaraDoor and Window Sensor P2, Matter Over Thread, Requires Thread Border Router, Contact Sensor with Remote Alarm and Local Automation, Supports Apple Home, Google Home, Alexa and SmartThings

These work flawlessly with Homekit and reliably trigger events with no false or missed events. They're easy to add to Homekit, they look nice and blend into your door or window frame.

I like Aqara products, have been using smart switches, wireless mini switches, motion sensors, wireless relays etc. Have around 50 devices installed at home. In the past i never had issues with its Zigbee devices. However its newer line of Matter devices (locks and Sensors) are not reliable. With time its U200 lock reliability has increased, no problems when used with the Aqara app or HomeKit. However not fully satisfied with Alexa integration, it is slow to react and disconnects continuously.The P2 window sensor does not work at all in any ecosystem, not even with Aqara. My experience is that it gets disconnected every other day. Every other day I had to reset it. I finally gave up and no longer use it. I realy do not know how this sensor could be used in an alarm system where reliability is paramount.

I love the Aqara P2 Door Sensors. They've given me peace of mind that my home is safe when I'm on the go!Even non-techies will find the setup of the P2 Sensor easy to accomplish. A warning to the wise, do not remove the sticky tabs until you understand exactly where on the doors the sensor is to be placed. I thought I had them positioned correctly until I realized I would pull the sensor off if I opened the door. I had to pull both parts of the sensor off my door to reposition them, but since the adhesive side is so sticky, I had to pull hard! They grip so well, that I can see them lasting for a lifetime of use.I've added the Aqara P2 Sensors and a Kasa Switch garage light switch to the home Apple ecosystem. With the two, I was able to create an automation that instantly turned the Kasa switch on when my Aqara P2 door sensor was triggered and turned off the lights 10 minutes later. I was amazed at how fast the Aqara P2 was able to turn on the Kasa light switch! I had to slowly open the door to see if the lights were actually off, otherwise, it looked like the lights were on before I opened the door it was so fast.This and the ability to ask "Siri, turn off the garage lights" is a huge win!

a disclaimer: I actually use this as a way to tell if my deadbolt is locked or not rather than the door being closed. But for everything else my impressions are the same.This is a pretty good product! I pull it out of the box. Set up a new device in google home. Scan the QR code. Wait a minute for google to finish the set up. Stick it where it needs to be stuck. Reapply it with some duck tape after the sensor fell off a few minutes after I set it. Yeah, the adhesion is great... after the glue has had time to set properly. So far that first time was the only time it's fallen off in the month that I've had it. So you just need to make sure that it is supported in some way for at least a few hours to a full day and it should be good after that.The software experience was almost dumb in how simple it was, which is exactly how a smart home device should be. It should be as close to plug-and-play as possible. The Matter standard makes this semi-feasible. I needed it to have matter for a different reason though. The long and short of it is that I don't have access to 2.4 ghz wifi, only 5ghz. So any smart device I get has to be able to connect to my nest hub in some way. Previously this meant scrouring for the rare smart devices that could connect to it with Bluetooth. But now that Matter is getting into the swing of things I actually have some options. And through matter its actually faster to respond than my old wifi and bluetooth devices! The bad news with that is that Matter is still a very new standard. With that come a few trade offs:1. you need a matter hub2. The new tech tax is certainly in effect here.While I'll take having an expensive option over having none at all. 30 dollars for a door sensor is pretty steep. (I got it on a black friday sale for around 20 though so keep checking if you want to save some money) But thats just something that comes with the territory I guess. So far all of the matter devices I'v bought have been more expensive than non matter counterparts. I'm sure as time goes on Matter will get support accross the spectrum of smart devices and prices will go down as the tech matures. But for right now we are still in the early adopter phase and you'll be expected to pay a little more..As far as the sensing part of things. It works. That's about it. It actually comes with 2 magnets which is nice. A pretty, white pill-looking one. As well as a flat, plain metal one that you can use instead of the pill if your situation demands a smaller profile. I do wish they would have put some way of knowing where the sensor needs to line up with the magnet to get it to work so that I didn't have to experiment with alignment as much. But that's a more minor gripe.

Stop!!!! Buy only if your going to get a home system mainly from this brand, if you want to use it with Google or Amazon or whatever, it will be a mission to connect to the 3rd party controller (AKA :thread board router)I had filled out the amazon return and was ready to head out to return this item, however I wanted to try one more thing, and this is the headache I had to overcome, I had to change my wifi to 2.5hz, turn off easy plug and play, turn off cellular data, and rearrange my thread board router in my units main app (Google home in my case). I don't know what did the trick but I got it and it work after the 15th time. No exaggeration.It does work fast and has a good battery in it. And it feels really well made. I only recommend if your ready for a mission or buying the whole system of the same brand. One more thing, this is one unit alone, the sensor and magnet, Not two or more.