The Quick Mailbox 4 in. x 4 in. Post Adapter can be used to attach any 7600, 7900 or 8000 Series Architectural Mailboxes post mount mailbox and many other mailboxes weighing up to 10 lbs. to a 4 in. x 4 in. wood post. The adapter plate is constructed of ABS plastic and resists fading and coloration. The easy to install design allows for multiple mounting methods – top mount, side mount and cantilever mount. The adapter includes mailbox mounting hardware and spacers used for T1 and T2 sized mailbox installation.