Theyre all wooden posts, set in cement. I don’t know how deep though… We hired someone to do it. They are definitely moving vertically, but I don’t think there’s any wobble from side to side… The latch is locking, and it’s about two inches tall, but it is always in line in the y axis, it just goes off up and down. Not sure if it’s both sides moving, but I know the gate is now also hitting the cement holding the opposite post.