Made entirely of aluminum, Salsbury U.S.P.S. approved 4800 series heavy duty rural mailboxes feature a 1/8" thick extruded aluminum body with a 1/8" thick die cast aluminum front door and rear cover. Heavy duty rural mailboxes also feature a durable powder coated finish and include an adjustable red signal flag and a magnetic door catch. The aluminum die cast door is attached to the body with a full-width stainless steel hinge allowing for smooth operation. Heavy duty rural mailboxes are approved for U.S.P.S. curbside mail delivery.