Bayshore interior rust and moisture guard.    Slides into place and fits all manufacturers 6 1/4" by 8" metal mailboxes.     Flexible arch made of ABS fits neatly and securely into the mailbox and conforms to the mailbox shape when pressed into the bottom corners.    The sleeve is black ABS and the tray is unpainted Aluminum.   The ABS arch is waterproof and highly rugged.      Bottom floor is made of aluminum and fits snuggly onto existing floor and is 18 1/2" in length.    Together the two pieces provide moisture  protection and cover holes in metal where bugs and other creatures may enter the mailbox.     The rust and moisture guard is designed to work perfectly with the RetroFit Mailbox Replacement Door