An enclosure shall have all of the following characteristics:
(a) Any access gates through the enclosure open away from the swimming pool, and are self-closing with a self-latching device placed no lower than 60 inches above the ground.
(b) A minimum height of 60 inches.
(c) A maximum vertical clearance from the ground to the bottom of the enclosure of two inches.
(d) Gaps or voids, if any, do not allow passage of a sphere equal to or greater than four inches in diameter.
(e) An outside surface free of protrusions, cavities, or other physical characteristics that would serve as handholds or footholds that could enable a child below the age of five years to climb over.