aokur Wireless Car Rear View CCD 170&deg; Review Backup Parking Camera In order to distinguish parking space, the standard reference line is make to thick tricolor keystone shape by green, yellow and red. Visual Angle lens: diagonal angle of 170 degrees, horizontal angle of 90 degrees. Transmitting and Receiving Distance: Barrier- free transmission signal 100 meters Receiver Sensitivity: -85Dbm Applicable Device:Car Navigation, DVD multimedia machine, car MP5 and car display.