Fabrics Car Camera Correction Calibration Cloth for 360 Degree Surround Bird View Panoramic DVR System Debugging parking position Debugging of DVR system for 360 degree closed aerial panoramic view Wire or Wireless:Wire Lens Material:Plastic+Glass Alarm Type:Remote Alarm Type:Accessories Alarm Type:Front Alarm Type:Front Side Alarm Type:Rear Side Length of Video Cable:2M Guiding Line:No name style:360 Degree Surround Bird View System Debugging Color:black+white Material:non-woven Package Contents: 4* Car checkerboard Only the above package content, other products are not included. Note: Light and different displays may the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.