... .3-10mmOpen area: 0.3%-63%Process: punchUse: Filter part, metal filter panelHole: round, square, diamondCharacter: winding-resisting, Ageing-resistingThe finished: electro-galvanized ... , hipboard, density board, plastic film, etc. Hole shapes:Round, rectangular, square, triangle, hexagonal, diamond, lightly pull scale, cross, slotted and special ...