Serve many tenants with just one unit by investing in this high quality 4C mailbox. It has 20 tenant compartments as well as an outgoing mail compartment. It is USPS approved and meets all STD-4C requirements for renovations and new construction. This unit is great for schools, apartments, residential complexes, and more. It will stand up to daily wear and tear, as it is made from tough aluminum with stainless steel components. Combine this with its corrosion resistant finish and you have a durable mailbox that is great to use indoors and out (with kiosk or other application, pending local USPS approval). Each tenant door is designed with a dustproof cam lock, and each lock has three keys. The outgoing mail compartment has a slot and protective hood as well as anti-fish comb for added security. Please contact us for specific unit measurements.