Salsbury 4B+ standard horizontal 3600 series mailboxes are ideal for colleges and schools, corporate mailrooms, government agencies and many other applications. A front loading door panel swings on a continuous hinge. One mailbox opening contains a master commercial lock and cannot be used for mail distribution. Units include factory installed 3/4" W x 1/4" D trim and a solid rear cover. Custom engraved placards (related item #3667) are available as an option upon request.