Please not that our post caps are true to size so if the post is a little over, they may need to dry or be sanded down somewhat for the post cap to fit properly. Our post caps are made to fit tight to help bind the post from splitting unlike others that do not. We believe post caps should serve a purpose to help preserve your post not just for decoration. If you want to understand this more, please see our post cap installation video for more details under the "installation" tab on our website.
Finial Size for 4x4, True 4x4 and 4x6 post caps are the same.
Finials for 5x5, 6x6, and true 6x6 are the same.