The 4-piece adjustable post skirt is designed to fit 3", 3.5", 4", 5", 6" and 6.5" square posts (actual size). The total height 1.226". The 4-piece PVC post skirt works with all of our post wraps (both 4" x 4" and 6" x 6"). The 4-piece post trim can be put on after post installation or added to an existing post since it is not required to slide over an existing post.