Salsbury vertical 3500 series mailboxes are ideal for colleges and schools, corporate mailrooms, government agencies and many other applications. Recessed mounted units fit into a rough opening and are secured with mounting hardware through the back or side panels. Recessed units feature a fully integrated flanged collar which fits over the rough opening. The rough opening for recessed mounted vertical mailboxes is 1-1/2″ less than the unit’s width, 1-1/4″ less than the unit’s height and equal to the unit’s depth. Private access vertical mailboxes include a master commercial lock with two (2) keys. Custom engraved self-adhesive placards (related item #3567) are available as an option upon request. Width: 35.25 in. Height: 19.00 in. Depth: 7.50 in. More measurements and details .