Disc image file created in the CloneCD Control (CCD) format; saves control information (track location and header data) for a corresponding .IMG file, which contains the disc image data is much larger in size than the CCD file. When mounting or burning a CloneCD disc image, you need the IMG file as well as the CCD file. The disc image may also include a .SUB file that stores additional disc data. If a SUB file is included, you may also need it to mount or burn the disc image properly.