Our heavy duty posts are designed specifically to accommodate our line of locking mailboxes. We offer an in-ground post for mounting in the dirt. We also offer a surface mount post if you have a sidewalk or concrete slab where your mailbox needs to be installed. Both types feature a 4″ x 4″ extruded 1/8″ wall aircraft grade aluminum tube. The in-ground post has a single mounting plate welded to the top and pre-drilled to match our mailboxes. The surface mount post has two mounting plates, one for mounting to the sidewalk/slab and the other for mounting to the mailbox. All necessary hardware is included and they come in four colors to match our mailboxes, black. brown, green, and grey.