USM UBBXX060404 Centurion Premium Classic Gloss Black Post Mount Steel Mailbox Approved by the US Postmaster General. Meets or exceeds all requirements for USPS-STD-7B Rugged plate-steel shell resists impacts from roadside hazards and vandalism. Weather resistant kiln baked powder coating finish provides superior protection against the elements. Patented Weather Barrier Door. A precision fit channel door that keeps moisture out. Calibrated magnetic catches to keep doors shut tight against harsh weather.