The Sensor Extension Cable comes with a mini-socket on one end and a mini-plug on the other end. The length of the Extension Cable is 8.2 feet (2.5 meters).  
 
It is used to extend the cable of a sensor if you find the length of the sensor cable is not long enough for your specific installation or application.
Simply plug the mini-plug of your sensor into the mini-socket of the extension cable, then plug the mini-plug of the extension cable into the mini-socket of the control box of your parking sensor system.  
 
Note: please be aware that some ultrasonic parking sensor systems may not work properly with the use of the extension cable such as giving continuous beeping sound or not work at all. And the only way to know if the extension cable will work with your parking sensor system is to connect it to your system and try it.