This cover and inlay should print to the correct dimensions. However, if they do not then set whatever software you are using to print them to proportional printing, then set the height for the cover to 11.9 cm, and the height for the inlay to 11.7 cm. This should ensure that the width automatically sets itself correctly.

If you have a transparent CD case, please use the image below on the inside of the tray.

Disc label for the CD...