The striking Hummingbird details make this more than your average mailbox. The deeply embossed designs show your love of nature and will last through a lifetime of weathering.. The Springfield Series Mailbox Post is a 4" x 4" x 78" smooth square post with decorative finial and mailbox mounting arm. Made of durable aluminum construction with a powder coated finish. Direct Burial Installation required. The Main Street Mailbox Post features a 4” x 4" square post with sculpted corners and accent flutes for a unique look. Made entirely of Aluminum with Stainless Steel components to eliminate rusting. Direct Burial installation required.