Two rear and two corner sensors emit audible beeps to the driver while backing up-signaling as the car approaches
Rear-corner sensors give off a high-pitch "beep" while rear-center sensors create a lower-pitch "beep"
Both high and low beeps quicken as the car gets closer to the object
An included on/off switch is mounted to the interior on the D-pillar to silence the system when it is not wanted
A separate back-up sensor attachment is required for installation
Installation costs not included.