[KJS]

In the first picture the sensors are located in the black area (above the tail pipe and below the back up lights) and in the second picture the monitor is located in the car on the rear shelf on the "backside" of the third stop light housing.
The monitor reads out the distance from an object and beeps more quickly the closer you get. Helps keep from running over small children who cannot be seen from driver's seat thru the mirrors, etc. Its amazing how many kids in parking lots straggle behind their parents, stop to pick up a toy, etc. Or when you are backing out of your driveway kids come running up the block and stop behind you as you start to back up.
God doesn't always look out for small children, drunks and idiots.