I had a little bit more trouble pairing these sensors to SmartThings than I have with other devices, but for the size and price of these sensors, I definitely think they are worth the effort. I'll likely be buying more when I find a new use case. Here is how I paired them with SmartThings:
On the contact sensor I pulled the battery tab
Used the provided push pin to put in the small hole and hold the reset button down for 3-5s (until a red light started blinking)
On the SmartThings app I tapped the '+' to add a device
Then clicked 'Scan nearby'
After 30+ seconds it discovers the device and calls it 'Thing' On SmartThings IDE (account.smartthings.com)
I logged in and click on My Devices
Click on the device I just named and clicked the Edit button
Change the DTH 'Type' to 'SmartSense Multi-Sensor' and clicked Update button
At this point, the app showed the right interface for the contact sensor when I looked at the device, but it showed disconnected (cloud symbol with a line through it). I then used the push pin on the sensor again to make it discoverable again to re-add the device from the app. After another 30 seconds of searching it discovered the device. The device was then working properly at that point.
🔵 Product Link: Linkind Zigbee Door Window Sensor