WIFI DOOR WINDOW SENSOR

That looks like a standard Tuya-based WiFi Door/Window Sensor. These are great for basic home security or automation (like turning on a light when you open a closet).
​Since it's a Tuya device, it's pretty versatile, but it can be a bit finicky during the initial sync. Here is a quick guide to getting it up and running.
​## Getting Started
​The App: Download the Tuya Smart or Smart Life app from your app store. They are essentially the same, but Smart Life is often slightly more polished.
​Power: Most of these use AAA batteries or a CR123A. Pop them in, and you should see a small LED blink on the larger unit.
​The "Pairing Mode": * Find the small reset hole or button (usually on the side or bottom