Made of electro-galvanized 20 gauge steel, Salsbury 4700 series mail houses include a stainless steel mail flap. Mail houses can be surface mounted, mounted on standard bolt mounted mailbox posts (#4765), standard in-ground mounted mailbox posts (#4795) or to a base of your choice. Each unit features a durable powder coated finish available in four (4) contemporary colors. Units are accessed from the front through a 13'' W x 9'' H locking door and include a lock with (2) keys. A non-locking thumb latch (related item #4788) is available as an option upon request. Mail houses may be used for U.S.P.S. residential door mail delivery.