The grid is made from recyclable white virgin PP (polypropylene) material, our proprietary manufacturing process rovidesa rigid honeycomb design that holds its uniform hexagon shape which provides maximum load bearing. All panel edges have an interlocking system that makes for easy installation, even on steep grades.  Stabilized gravel. Get gravel to stay put, no ruts, no sinking, no problems It's green. Environmentally friendly porous paving allows the rain to drain over entire surface.