Salsbury column mailboxes are available in a cast aluminum style or antique brass style and are designed to be recessed mounted in columns, masonry or walls. Made of die cast aluminum, Salsbury 4100 series CAST ALUMINUM COLUMN MAILBOXES are available in a LOCKING style (#4145) and a NON-LOCKING style (#4140). Each model features a durable powder coated finish available in four (4) contemporary colors and two (2) door designs (plain and eagle). Salsbury ANTIQUE BRASS COLUMN MAILBOXES are handcrafted in solid brass to provide a custom look. Antique brass column mailboxes are NON-LOCKING and include an antique brass door and handle and are accessed from the front. Cast aluminum column mailboxes and antique brass column mailboxes may be used for U.S.P.S. residential door mail delivery.