The surface has two layers of PP co-extruded layer, the scientific name of thermoplastic polypropylene, it can make the surface of the plate more resistant to impact, at the same time in the construction can repeatedly fold the edge of the corner, not easy to break, plus the middle is a porous honeycomb structure, not easy to deformation, in order to meet the plate lightweight at the same time, but also increased the effect of sound insulation and noise reduction.