This secure 4C Standard Mailbox unit is constructed of heavy gauge aluminum with stainless steel components for maximum durability both indoors and out with an included shelter. The corrosion-resistant, weatherproof powdercoat finish protects the units from the elements, while the riveted shelves and concealed hinges limit pry points for extra security. The mail carrier access door provides easy access for Postal Letter Carriers to release the master loading doors. Each tenant door meets the new compartment minimum size requirement of 3"H x 12"W x 15"D while the mailbox unit overall meets the USPS requirement for 1:10 parcel locker to tenant compartment ratio, and the USPS 4C requirements which comply with ADA standards.