Ring Alarm Contact Sensor 2-Pack - 2nd Gen | Instant Window & Door Alerts | Approximately 3-Year Battery Life | Slim Design |
4.7 | 28,458 ratings
Price: 39.99
Last update: 12-06-2025
About this item
- Get instant mobile alerts when doors and windows open in your home with a Ring Protect subscription (sold separately).
- Now smaller to enable increased placement options.
- Easy installation with no tools required.
- Mounts to door and window frames.
- Includes two 3V CR2032 batteries.
- Requires the Ring Alarm Base Station.
Top reviews from the United States
- Always Read The Reviews FirstRing is rage inducing garbage - the more you buy, the more troubles you will haveBackground: I have about $1000 invested in ring equipment - two systems, multiple contact sensors (1st and 2nd second gen), cameras, doorbells, floodlights, etc. It started off (relatively) easy - setup is awkward but with a couple of items only it seemed to work reasonably well and was convenient and not too expensive.
The problem comes when you add more devices to the system - more devices invite more trouble and the truth of the matter is that ring is mediocre equipment that requires a frustrating app that is meant to hold your hand through new setups and not fix existing problems.
My latest round of problems come from a system I set up early march 2023 (less than 5 months ago). Three days ago the motion sensor detected motion while I was gone - even though there was nothing in the house. Only option while I was shopping was to completely disable the alarm. The next day the front door sensor completely stopped responding (the battery indicator on the app said full batteries, so that shouldn't have been the problem.) I swapped it out with a spare sensor and two days later that sensor, the back door sensor, and the living room motion detector all stopped responding at the same time.
And that leads me to the big problems with using ring: There is no app side reset function because everything requires either a button press on the item or opening it up to do a reset with a paper clip. So if you're at work, on vacation, or monitoring a second home, you have to actually go there to fix things. This is a glaring fault, either caused by ignorance or arrogance - maybe they don't think their equipment will malfunction (trust me, it does) so they don't make it easy to fix. In fact it's often easier (even required) to completely remove the device via the app and start all over.
Another note on the app: It's poorly designed and unfriendly when it comes to adding / removing equipment. For example, if you try to set up a sensor and the installation fails, you can't jump right back to the main menu and start over. Instead you have to hit the back button 7 or 8 times until the option menu appears again. Try doing this over a dozen times for each failed installation. That's one of the reason I called it rage inducing.
Right now it's sunday night. I've spent over two hours trying to get my system up and running again so I can go to bed. Instead I get notifications that things can't connect or that they've been tampered with (they haven't) and the tamper reset instructions online just don't work (and of course there is no reset in the app itself, why would there be - ring is perfect, don't you know). Now I have to wait for my phone to charge up enough so I can spend another hour trying to get the last door sensor online again.
Do yourself a favor - if you're going to get more than a couple devices (more than a front door and back door sensor and a ring doorbell), find something better. When I move I'll be switching to a different system that is hardwired and reliable and maybe give the ring system to someone I don't like. - AaronBuy for added securitySensors are easy to install and integrate seamlessly with the Ring system. Occasionally there’s a slight delay in notifications, but otherwise reliable. Lost one star for the minor lag, but solid security addition
- Jesus L.Easy to Set Up and Works Great!I picked up the Ring Alarm Contact Sensor for one of my entry doors and was really impressed with how easy the whole process was. Setup was super simple, basically just pulled it out of the box, followed the app instructions, and it connected without any issues.
What I really liked is that it already had adhesive tape applied, so I didn’t even need to dig out tools or screws. I just peeled the backing off and stuck it directly to the door and frame. Took maybe two minutes total.
It’s been working perfectly since, alerting me right away whenever the door opens. It’s a solid little sensor and blends in nicely without being too noticeable. - sandra dylkaNeed Ring Alarm Base to useI wish I knew in advance that to use these, you need the Ring Alarm Base, which costs about $100.
- saravaDevice became defective after 2 years!This product worked well for 2+ years. Last weekend while we were out this one door sensor started beeping that it was tampered. And Police had to come check the house. The tampering issue continued for over 2 days almost every second for hours together and then would suddenly stop and start again. The battery is fine. And finally when we came home the sensor was absolutely intact. Dont understand what went wrong. Buying a new 1 to replace it
- Steve H CheungRing Alarm Contact Sensor with SmartThings Hub v2Ring Alarm Contact Sensor works perfectly with SmartThings Hub v2. Very easy to setup.
Add device by scan QR Code, remove small piece of plastic to activate battery, press button for 5 seconds. when you release the button, it flash really quick during pairing with SmartThings Hub. it should show up as Z-Wave device when is done. - DW SmithI always know when someone opens the door!The Ring Alarm Contact Sensor alerts me when a main door opens without fail. The installation of the sensors on windows was much easier than on the doors. One main issue is a piece of trim, a part of a sidelight, that prevents the door from lining up properly for an easy sensor install. If y'all are having a similar issue, you might want to try this simple solution. I found that the adhesive strips lost the adhesive quickly, due to my continuous removing & replacing the sensor components, trying to find a suitable spot. I tested each spot to see if there was enough contact area to sound the alarm when I opened the door. Needless to say, this process was was tedious, time consuming, and infuriating! After considering several other options, including cutting notches in the trim, ( I was that desperate), I thought about those 3M picture hanging strips and they just might provide the extra lift to bring the contact area up enough to sound the alert. Hey, what would it hurt? Success! It worked! I did have to cut some strips to fit the components, but that was not a problem. The best part of this solution is that I didn't mangle the trim and the sensor can be easily removed and replaced for painting or if we ever move to another house. I hope the majority of y'all won't ever need these directions. I am giving this product good ratings based on the install on windows and deducting 1 star for my door situation. FYI, I've used the non-picture 3M strips to secure the alarm keypads. I'll post pix/video later today/
- Mac50/50 that new sensor will workSome sensor are defective