A letter cage is useful to have especially if you have pets or animals around. They are manufactured in many different colors, styles, shapes and designs. You can purchase any color you want as they are available in brass, black or white finish. They are usually made of steel or brass metal. A letter cage can vary in size and you can get a size to suit your needs, whatever they are. In the UK there are quite a number of different colors available than in the United States of America. Their installation process is relatively simple as they are placed over the mail slot on your mail box and it is screwed onto the door with four screws. Usually the process involves damage to the door and the paint of the door and this is noticeable once you remove the cage. In this case to temporarily repair it, you can try painting over the holes of the door