Heavy duty post, Solid heavy gauge steel that is beautifully finished. It is slightly larger than a wood 4x4 and has threaded holes for the enclosed m8 bolts. (For the mail box) I slipped inside it a wood 4x4 to make it longer and even stronger. A 4x4 easily slips inside and it comes with lag bolts to attach at the bottom if desired.  I think though the post should be at least 6” longer. I buried mine 2’ so needed the 4x4 for the extra length.  It is rock solid! 31” finished height from the street was a bit low for my mail lady. Even though is it 1” higher than postal minimums when the mailbox is attached. So I ordered a mail boss ht extension that will give it 6” more. Not cheap so I would install it at least 33” -34” high from the street level  not 31”.  My mail lady said the new mail trucks have higher window levels. The post is expensive but beautiful and custom made for any mail boss mailbox.