There are many types of reverse parking sensor system. Basically we can seperate into three catagories: 4 sensors system, 6 sensor system and parking system with rear camera.

4 sensors system consists of a simple monitor showing left and right distance, 4 pieces of radar sensors and a main unit. It is the most easy DIY system. Buying tips: avoid fancy monitor, simple monitor with left and right LED light bar and central digit display will help to make parking much easier. Less confuse. Buzzer is definitly a good option.

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6 sensors system consists of a monitor, 6 pieces of radar sensor and a main unit. The sensors distribution are: 4 sensors to be installed on the back and 2 sensor to be installed on the front two corner. This will help driver to watch out for the front two corners of the vehicle. The two front sensors will only be activated when brake pedal is pressed. There are two types of monitor: VFD and LCD monitor. LCD may not be seen clear during stronge sunlight, while VFD can be a all climate display. Simple and easy to be seen.

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Parking system with rear camera: the system usually consists of a night vision CCD camera, 4 radar sensor. Some of the system even come with monitor (such as the clip on rear view mirror with 7" TFT LCD). This system a ultimate system for parking or reverse aid. Driver can view what is going on the back of the vehicle day or night. The rear view mirror with TFT can also act as normal montor for TV/DVD, GPS etc.

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