Mailbox Drive-In. Post Kit, Cedar With Steel Anchor, 41 x 4 x 4-In.The sturdy easy install cedar drive in post is crafted from beautiful, aromatic natural red cedar and a terrific addition to any residence. slight variations in the natural wood grain give the post a one of a kind appearance. this drive in post comes with a steel anchor, which eliminates the need for digging or installing the post in concrete. pre notched for easy assembly, the post is intended for use with medium sized and large mailboxes.