It’s one of those freshnel lenses you glue to your rear window to act as a fisheye lens. It’s actually surprisingly good. I can see the ground about 1.5m (5ft) behind me. I wish it would reach my rear bumper as that’s what I’d like to see but this helps!
Also, I took the picture with a poor man’s smartphone - my apologies.
Love the simple elegance of it. It just works, no subscription, nothing to break, nothing to fix. And all the money you saved can be saved or spent on what is important in life.