The traditional shape of our Classic Curbside Mailbox is the only thing this mailbox has in common with a standard hardware store mailbox. The solid cast aluminum construction, with 20% thicker walls than our competitors, provides added strength and the powder coated finish will maintain a lifetime of beauty. 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.