Garmin Varia RCT716 Radar

Networked rear light with camera and radar recognises what is happening behind the saddle.

... Compared to the RCT716 model sold in Germany, the international version RCT715 has a flashing light mode that is not permitted in this country. Those who do not value the camera function are better off with the RTL516, which is only half as expensive. If you only need a camera but no radar, you can buy the Cyclic Fly6. For many, however, a rear-view mirror on the handlebars would also do.