ABOUT PARKING RParking are proximity for road vehicles designed to alert the driver of obstacles while parking. These syst use either electroic ulsonic .These syst feature ulsonic proximity s to measure the distances to nearby objects via located in the rear bumper fascias or visually minimized within adjacent grills or recees.The emit acoustic s, with a control unit measuring the return interval of each reflected signal and calating object distances. The system in turns warns the driver with acoustic tones, the frequency indicating object distance, with faster tones indicating closer proximity and a continuous tone indicating a minimal pre-defined distance.Rear may be activated when re gear is selected and deactivated as soon as any other gear is selected.As an ulsonic syst relies on the reflection of sound waves, the system may not detect flat objects or object insufficiently large to reflect sound — e.g., a narrow pole or a lonudinal object pointed directly at the vehicle or near an object. Objects with flat surfaces angled from the vertical may deflect return sound waves away from the , hindering . Also soft object with strong sound absorption may have weaker , e.g. wool or mo.Features:Rate voltage: 12V DCRate operating range: 10.5V - 16V DCRate current: 100mA - 300mADetecting distance: 0.3 - 2.0mUlsonic frequency: 40KHzControl moudle working temperature: -30 - 80 celcius degreeMain control box size: 90* 61 * 22mmr's Diameter: 22 mmPackage including:1 * Main Control Box1 * display (Beeper Designed In the Display)4/6/8 * Parking 1 * Hole 1 * Power Cable2 * Double Side Sticker1* User manual