The next step is to add the support posts to the back plate to keep the iPad from sliding - when in landscape. We were going to be using this only in landscape mode. You may want to consider adding another sliding support if you want to use it in portrait mode. To create the slide support stops, use the screws and the threaded posts in the two interior bottom holes on the bottom of the back plate. Insert the screws from the back-side of the plate and screw the posts on the inside of the back plate. These posts differ a little from the ones we use for the side as they are threaded. The last photo here shows the iPad resting on the posts.