Two smooth rails across the top.   Pickets also protrude through the bottom rail 2”.  Meets BOCA code for pools. Ships fully assembled in “six foot” wide panels. Actual panel dimensions are 71 3/8” widths, creating 73 3/8” wide panels on center when installed. Panels include (15) 5/8” square pickets and horizontal channels measuring 1” x 1 1/8”.  Standard picket spacing is 4 ½” on center, providing 3 7/8” air space between pickets.