STD-4B+ and Private Horizontal
Available from Florence Manufacturing Company
If residents would like to increase the security of their existing STD-4B products without doing a complete mailbox replacement, Florence offers a STD-4B+ security upgrade kit for its mailbox products. While not able to fully bring the security up to the new STD-4C standards, these upgrade kits will enhance the security of the existing STD-4B box by hardening the arrow lock master door; typically the most vulnerable portion of older mailboxes.
