Salsbury Industries 4870WHT Deluxe Mailbox Post 1 Sided, In-Ground Mounted, White Item may ship in more than one box and may arrive separately 1-sided deluxe mailbox posts include a 14" W x 3-1/2" D x 3-1/2" H arm 2-sided deluxe mailbox posts for two mailboxes include two 14" W x 3-1/2" D x 3-1/2" H arms 2-sided deluxe mailbox posts for three mailboxes include one 14" W x 3-1/2" D x 3-1/2" H arm and one 23" W x 3-1/2" D x 3-1/2" H arm 2-sided deluxe mailbox posts for four mailboxes include two 23" W x 3-1/2" D x 3-1/2" H arms 2-sided deluxe mailbox posts for five mailboxes include two 14" W x 3-1/2" D x 3-1/2" H arms and one 36-1/2" W center bridge