https://www.cnet.com/news/wyze-cams-new-friend-the-20-wyze-sense-security-kit/

Available for preorder now (via the Wyze app, meaning you need to already have a Wyze Cam), the Sense consists of four components: the bridge, which plugs into the back of the camera (so that's what that USB port is for), two contact sensors and one motion sensor.

The contact sensors are designed for things like doors and windows -- basically anything that can be opened or closed. When either activity occurs, the sensor will trigger the Wyze Cam to start recording, or just send an alert to your phone. The motion sensor can do likewise.