electromagnetic parking sensor

hi... I have been purchase a electromagnetic reverse parking assistance sensor. I wondering about this device. It is just using thin metal band for the sensor around 150 cm length and 2cm width. How is the basic circuit for this device? Many thank for the attention.

Regards

You have it in your hand and we don't. Could you possible give us a few clues to what you have?

paul

I want to made arduino rear parking based electromagnetic. That is like many product sell but till now I still not found the schematic. The parking sensor base ultrasonic and infrared are many found in the internet but not for electromagnetic type.