

🚪 Stay Secure, Stay Smart — Never Miss a Beat at Your Doorstep!
The THIRDREALITY Zigbee Contact Sensor 4 Pack offers robust, reliable door and window monitoring with effortless setup and 2-year battery life. Compatible with major Zigbee hubs and Echo devices, it supports smart routines via Alexa and provides real-time status updates through the Third Reality app. Ideal for professionals seeking seamless home automation with trusted performance and proactive alerts.

























| ASIN | B09XCZJMC5 |
| Batteries | 8 AAA batteries required. |
| Batteries Included? | No |
| Batteries Required? | No |
| Battery Cell Type | Alkaline |
| Best Sellers Rank | #19,807 in Tools & Home Improvement ( See Top 100 in Tools & Home Improvement ) #33 in Home Automation Devices |
| Brand | THIRDREALITY |
| Color | White |
| Customer Reviews | 4.4 4.4 out of 5 stars (1,124) |
| Date First Available | December 3, 2021 |
| Description Pile | Alkaline |
| EU Spare Part Availability Duration | 2 Years |
| Included Components | Door Sensor × 4; AAA Battery × 8; Double-sided Tape × 4; Screw × 8 |
| Item Package Quantity | 1 |
| Item Weight | 10.2 ounces |
| Item dimensions L x W x H | 1.97 x 0.83 x 2.36 inches |
| Item model number | 3RDS17BZ |
| Manufacturer | Third Reality, Inc |
| Material | Plastic |
| Measuring Range | Binary: Open/Closed |
| Mounting Type | Door Mount |
| Output Type | Digital |
| Part Number | 3RDS17BZ |
| Power Source | Battery Powered |
| Product Dimensions | 1.97 x 0.83 x 2.36 inches |
| Smart Home Compatibility | Smart Home Compatible |
| Specific Uses For Product | Contact Sensor |
| Style | Door Sensor 4 Pack |
C**Y
A bit big, but it's ThirdReality so it just works
These are great door/window sensors that have been super reliable for me so far. I was tired of a few other brands falling off my Zigbee network, so I went to trusty ThirdReality and haven't been disappointed. They are a bit bigger than alternatives, but that's because they pack a couple of AAA batteries which I expect to last a long time (given their record with other Zigbee devices). It's been several weeks and no battery issues so far; I would guess they'll last months or even years depending on usage. ThirdReality is also a Home Assistant partner, which means they actually test their stuff with Home Assistant and ZHA for their Zigbee stuff. It's perfectly compatible with my Sonoff Zigbee radio, as well as the Home Assistant ZBT-2 I recently switched to. They're a bit on the large size and not particularly pretty, but I don't think you could find a more reliable contact sensor for doors or windows (or drawers, or car chargers, or toilet lids… whatever you freaks are automating!) or a better value anywhere else. If you have the physical space, I'd highly recommend them!
S**B
Simple, Reliable, Power Efficient
I purchased these to help with various automations around the house including turning lights on and off, warning if freezer/refrigerator doors are left open, etc. and they work perfectly with my Home Assistant setup. The devices were instantly recognized by my Sonoff Zigbee 3.0 USB Dongle Plus (connected to my Pi5 running Home Assistant) and I could setup everything from there. So far, zero complaints as they work like a charm. For those folks frustrated with the mounting tape included with these such that upon removal the devices can crack, I simply used 3M Command Damage-Free Hanging Strips to make moving them super easy. Attached is a picture of the one I have installed atop the inside of my pantry door. I moved it from one spot to another using the Command strip and it came off damage free.
T**A
Brilliant product, easy to set up and use in Homeassisstant
Brilliant product, I have it installed all over the house and haven’t had to touch it since I got it into HomeAssisstant. Batteries might have to be changed at some point, I recommend getting rechargeable ones for that.
D**D
Good, but with one surprising caveat
Overall I’m pleased with these sensors. I like that they use AAA batteries Compatibility is fine - I haven’t had any issues with their connectivity (I use a mix of Zigbee vendor devices off a Sonoff Zigbee dongle). Detection range of the magnet is OK, but can be a little tight depending on this next factor: Something that is very strange about them is that the two parts of the sensor are not the same thickness. The main body is quite a bit thicker than the small magnet. This means that if you mount them on a level surface, they will not be level with each other! Depending on your situation, this can affect detection. A strange choice, but not a deal breaker for my use cases.
S**R
Best choice
Love these sensors. They pair almost instantly and are a great addition for my home assistant setup to automate all my lights. I’m also using them for my own local security system. Definitely the best value out there for sensors. You can’t go wrong with any Thirdreality product.
J**7
Washing my entire life away trying to get ecosystems to work
There’s nothing I love more than spending hours at a time on Friday night trying to understand how to connect devices to my 87 different ecosystems that for some unknown reason aren’t compatible with one another. Between SmartThings, Apple home, Aqara and Alexa you’d think that a stupid matter compatible device such as this would work. But in order for that to happen I’d need a matter qr code which these don’t have… I consider myself quite tech savvy but I’m just about done spending my free time trying to get these stupid things to work. That includes Aqara, Apple home and SmartThings which can all choke for all I care. I was able to get Alexa to work in the past but it’s not as if that was easy either. Waste of money, not compatible, inaccurate and frustrating. I hate this and all other smart home devices and I’m done spending my time trying to figure this out. I’d rather have a dumb home and protect myself with my small Louisville slugger as my security system.
M**P
Works with Abode Security
Works as expected with an Abode Smart Security System. Pairing is a little finicky. It seems if you put the hub into 3rd party device pairing mode, put the sensor into pairing mode, wait for the blue light to stop flashing, then trigger the sensor, it pairs quickly. If you don’t trigger it, it seems to not want to pair. It may take a few tries but it pairs and works reliably with good range.
A**W
Very Happy User
These are GREAT sensors so far. Had them installed for about two weeks now and zero issues. The install and integration to my Smarthings environment was easy. In fact, these were the simplest devices to find and add to the n/w I’ve ever experienced - normally I have to stand on my head, face north and contact some spiritual being to add sensors 😜 One other functional item I’ll note is the distance between the two parts can be fairly large, like over an inch, and still work. There’s an embedded LED in the receiver that lights when the transmitter (magnet) is sensed, which is super helpful when installing and checking functionality. Anyhow, I’m planning to buy more!
D**R
Het item voldoet volledig aan de eisen
R**B
I bought 12 of these to replace all of another brand (S*O*N*O*F*F) which uses 2032 button cells, they paired with any of the Hubitat models within about 10-15 seconds whether they were 1m or 10m away. The driver it picked up was the built in Generic Zigbee Contact Sensor (no temp) They all needed an upgrade from 0x30 to 0x3F which was easily done via Hubitat within about 10mins, about 60 secs per 10% block, the progress can only be seen in the live logs for the Hub. This gives you: Optimized the network joining and reconnecting algorithms Optimized the power detection logic Optimized the trigger filtering algorithm From what I have experienced, the upgrade procedure is well protected and never bricked any of them, each 10% block is transferred and checksumed, at 100% the upgrade is transferred to its flash memory. The device still has live operation during the upgrade process. I made a mistake on the first one by unpairing/re-pairing while it was upgrading, simply because I did not realise anything was happening viewing the device page. When I found where I could see the progress, it had stopped at 30%, after 2 mins I realised the upgrade had been cancelled by my actions without any harm. The upgrade was just started again and completed without error. The great thing about these 3rdReality devices is that they use a modern hall effect sensor to trigger via the magnet instead of an antique reed switch, so they can be mounted offset slightly on windows and doors, the max detection range is about 25mm so best to stick with 15mm or less if the magnet is not on the same plane. As long as you dont have any poor/ chatty/ proprietary Zigbee protocol devices on the Hub and have good plug in repeater mains sockets between far off devices to create a good Zigbee mesh they operate automations in Rule Manager within a second , no matter how far away they are from the Hub. I am very impressed with this brand and have purchased 8 Temperature/Humidity lite sensors, again uses 2 x AAA supplied and also a couple of the waterproof soil moisture/temperature sensors to assist in the automated garden watering .
K**N
Works perfect, easy mount and setup Recommended
A**A
Funciona de lujo, raros son los que pueden tener tal espacio de detección. Además, usando pilas normales, fácil cambiarlas y recargarlas. La única pega es que usando pilas normal, pues es un poco más grande, claro.
P**G
Distance d' ouverture : jusqu a 3cm - 2 piles AAA, toujours sur d avoir un capteur qui fonctionne, trés vite reconnu par HA
Trustpilot
2 months ago
3 weeks ago