Ring Door View Cam spies on visitors through your peephole at CES 2019
https://www.cnet.com/news/ring-door-view-cam-spies-on-visitors-through-your-peephole-ces-2019/
Remove your existing peephole, place the Door View Cam on the front and back of the door, along with the battery and the removable faceplate.
Ring's Door View Cam comes with: