Letter plates, or letter box covers from The Door Knocker Company are cast using traditional methods from brass or iron and are either polished and left to age naturally or lacquere, chrome or nickel plated. The iron is finished with a black powder coating. Letter plates keep draughts out of the house as well as adding a decorative element to the front door. A brass, chrome or black inner tidy, keeps the inside of the door tidy too. Letter box covers can be plain or decorative, often letters is written accross the flap or there may be an inclusive door knocker or rapper.