I wanted to post this as a new thread but my browser keeps quitting when I select new thread. Anyway just to let users know that my system ( Honda Fitted) does not give adequate warning when reversing up to a low wall of 260 mm high. Having checked it out, I get a double beep at 1.2m , then another beep at 0.8m, and nothing after that. Raising up the obstacle height to just below sensor level and the systems functions as designed. So beware of low profile obstacles.
I would be interested to hear of others experience.
CISBO Parking Reversing Sensor 4 Sensors Audio Buzzer | eBay