(a) There must be loose-fill surfacing material or unitary surfacing material in the use zones (area around and under equipment where resilient surfacing is needed to prevent serious injury from occurring as result of a fall) for all climbing, rocking, rotating, bouncing, or moving equipment, slides, and swings.(b) The height of the highest designated play surface on the equipment will determine the depth of loose materials or the attenuation rating (thickness) of the unitary materials.