I had a hard time finding any info about these before buying them so I just wanted to post this here for any future people considering getting one. I needed some more z-wave door sensors for my house and was looking around for good deals. The best ones on the market tend to be rather pricey (around $30-35 each). Ultimately I decided to take a risk based on a single post in the ST community that mentioned that 2nd Gen Ring sensors worked fine and they do!
I got this one from BestBuy for $20 (so I could return it if it didn’t work) and have since bought 2 more. They paired easily with ST in S2 authenticated mode and have worked flawlessly.
Notes: You need to hold down the button on the sensor for 4 seconds the first time you turn it on to switch it to regular pair mode, then ST can find it. You add the device by scanning the QR code and then scanning it again to secure the authentication when prompted. Once added, it will add as a “z-wave sensor” device type, so you need to go into your smartthings ide and change the device type to “Z-Wave Door/Window Sensor”. After that, everything works perfectly!