What does the mailbox attach to?

You must dig a hole for the 4 x 4 post(which is not included), then set your post in concrete, then let it set over night. The next day, you can back fill, and mount your post using two lag bolts, with two washers.

You dig a hole in the ground, place the 4X4" post in, and pour concrete around it. Then, this mailbox kit will hook to that 4X4" post.

to a secured wooden 4 x 4" post or pipe that is inthe ground.