It's a simple LED trailer light - $ 30.00.
It is mounted on the rear tow loop... which might not be the best place
( there are not too many choices ), but if a tow truck driver is dragging me back up onto the road, I've got more to be concerned with than him messing up a $ 30 light.
It's wired into the ignition, so that when I shut the car off, the light goes off.
It is very bright... I can actually see the reflection of the light on the pavement thru my driver's side rear view mirror.