Made entirely of aluminum, Salsbury U.S.P.S. approved 4800 series heavy duty rural mailboxes feature a 1/8" thick extruded aluminum body and a 1/8" thick die cast aluminum front door and rear door cover. Heavy duty rural mailboxes also feature a durable powder coated finish available in four (4) contemporary colors and include an adjustable red signal flag and a magnetic door catch. The die cast door is attached to the body with a full width stainless steel hinge allowing for smooth operation. Heavy duty rural mailboxes can be mounted on standard, classic, decorative, or deluxe mailbox post, spreaders or a base of your choice. Rural mailboxes are approved for U.S.P.S. curbside mail delivery. Heavy duty rural mailboxes are manufactured to USPS-STD-7B specifications. Salsbury Industries is an ISO 9001:2008 certified company and has excelled in the field of manufacturing since 1936.