The rear-loading 1700 series horizontal mailboxes are designed for use in large, private installations not serviced by the USPS such as colleges, offices, and military bases. Tenant compartments measure 4" x 5" with 5-pin cam locks, and come with two keys each, and a clear plastic number slots for tenant identification.

The smaller compartment size does not meet USPS regulations, however because more mailboxes can fit into each module, it is very useful when working with limited wall spaces. The private distribution 1700 series lockable mailboxes do meet all other USPS regulations.