1.Fiberglass mesh 2.Advantage: heat-keeping, dielectric, corrosion-resistance 3.reinforce cement, plastic, ... , waterproof, heat-keeping, dielectric, flat surface, longtime-using, and etc.2>hole: 5mm X 5mm, 4mmX4mm, 3mmX3mm3>mesh: 16X16 mesh, 15 X14 ...