... customers' requirement. ZRHH Mild steel perforated metal 1 Weaving and characteristics:Stamping ... hole, round hole, square hole, triangle hole, the scales hole, bridge type hole, lozenge hole, the hole, hexagonal hole, horoscope hole, the hole, nail hole, the plum blossom hole, herringbone hole, H hole and other shaped hole ... building wall body, generator room, factory workshop, and other noise source ...