This OLD WORLD IMPERIAL ESTATE PLAN MAILBOX fits on the: Estate, Windsor, Barcelona, ˜Century and the Americana post. All Single Mailboxes will come with a Brass knob unless the brass ring is asked for. Imperial Mailboxes and Posts are constructed of cast aluminum and covered in a premium, enamel paint so it is impervious to rust, insect damage and harsh elements. Imperial mailboxes and posts are not only approved for all new construction, but enhance the beautification of a residential, commercial or governmental developments. This Estate Mailboxe are Larger then the standard size. The Estate mailbox measures ---12''H x 10''W x 21.75''D