

🚪🔔 Stay ahead of every open door moment—smart security that just works!
The THIRDREALITY Zigbee Contact Sensor 4 Pack offers reliable door and window monitoring with seamless Zigbee compatibility across major smart home hubs like Echo, SmartThings, and Home Assistant. Featuring a 2-year battery life, quick Alexa-enabled setup, and customizable routines, it empowers professionals to secure their homes effortlessly while staying connected through real-time alerts and app-based monitoring.

























| ASIN | B09XCZJMC5 |
| Batteries | 8 AAA batteries required. |
| Batteries Included? | No |
| Batteries Required? | No |
| Battery Cell Type | Alkaline |
| Best Sellers Rank | #16,330 in Tools & Home Improvement ( See Top 100 in Tools & Home Improvement ) #39 in Home Automation Devices |
| Brand | THIRDREALITY |
| Color | White |
| Customer Reviews | 4.4 4.4 out of 5 stars (1,095) |
| Date First Available | December 3, 2021 |
| Description Pile | Alkaline |
| 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 |
| 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.
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.
N**E
Good cold weather sensor.
Works well most of the time. Occasionally, it will not function, but still worth it. Good sensor if you have it in cold weather as it uses alkaline batteries instead of lithium ion. I have mine in my garage mounted to my attic ladder to turn the lights on when opened.
C**A
Good Wyze Sensor Replacement
SIZE: Smaller than expected, it was described in millimeters, and the conversion just didn't work in my head (30mm = 1.1811inches)??? Now I can carry it with me and see what it fits into. SETUP: It was easy to connect to the Samsung SmartThings app. It reports actions very quickly, like within a few seconds, versus Wyze, which took at least 10 seconds. PLAN: Now need a way to make it waterproof so it can be used on the mailbox. The goal is to replace the Wyze contact sensor, which gave me a notification that the mailbox had been opened when mail was delivered.
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!
T**K
Unreliable. Disconnects. Do not buy.
Very unreliable. Was using it for a laundry room and it wasn’t good for that, wouldn’t dare use this for anything involving safety / security. Disconnects from the hub which is 10 feet away. I have had to unpair and reconnect it twice and still doesn’t stay online. Do not recommend this product.
A**R
Simple and easy to use
I set these up with home assistant and SLZB-06M with ZHA. Red light blinks on when closing or opening. The sensitivity is great so I can know if my door is cracked open even a tiny bit. Reliability has been great so far. I appreciate that this uses AAA batteries, which are cheaper and easier to find than button cells.
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
1 month ago
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