Review on SS4 Black Rear Drill-in Parking Assist with Sound-Only Backup Sensors by Bob Moonin

- broken out of the box - regularly squeaks when nobody is behind the car. - The sensors are not adjustable at all, neither in angle nor in sensitivity. I have an externally hung spare and the sensors catch it and turn off the sound as they have a very wide field of sensitivity. At the end of the bumper I have a plastic license plate frame on one side, which also triggers the sensor. If you tilt the sensors slightly towards the ground to avoid detecting a tire or license plate frame, they turn off. So this set is useless for me. If you have a plastic bumper, get the latest technology, search "electromagnetic reversing sensor". Revain has them, and they're much better, cheaper, and easier to install. Bottom line: if you have a metal bumper, first make sure there aren't any external obstacles near a sensor like tires etc that could cause them to work. Buy such ultrasonic sensors, just buy another brand.