Make a strong statement with our Westhaven post-and-beam style 4″ x 4″ aluminum square Mailbox post systems. Mailbox post system features a durable, low maintenance powder coat finish that will look great for years and comes with a Lewiston Cast Aluminum Mailbox, support bracket, decorative finial and square base. Lewiston Mailbox is non-locking and is made of cast aluminum with a matching powder coated finish. Post mounts directly into ground.