U channel: 30x30 5800 with cover.
 
Mready fencing provides a perfect solution for slat fencing with screw covers at back. This is an easy way to slide slats in and cover screws from the back. The fence would get the best looking no matter from inside or outside. 
To assemble fencing panels, U channels need to be fixed to posts at each side. And then put slats into the U channel and screw slats from the back. The U channel cover which is a C shape can cover all screws used.