As of October 6, 2006, USPS STD-4C compliant mailbox systems are mandatory on all NEW CONSTRUCTION and MAJOR RENOVATIONS. Mailboxes that are 4B+ compliant will
only be considered USPS Approved if they are replacing existing mailboxes in an existing rough
wall opening that is not being disturbed or changed during the renovation. If you have USPS
compliance questions related to your specific project, please contact your local Postmaster.
It is strongly recommended that you acquire local Post Master approval BEFORE ORDERING
any 4B+ product. Orders can not be canceled or returned.
Auth-Florence 1400 and 1500 Series Horizontal Mailboxes are designed for use in larger multi-family apartment buildings, dormitories, office highrises, etc. They are constructed of heavy-gauge aluminum. Front-loading boxes require one compartment to be a master door for Postal Service use. Rear-loading boxes require a rear cover. All horizontal mailboxes are recessed mounted.