... Black,Red5.Edges: square / beveled / tappedGlass Magnesium Oxide Board is a kind of environmental-friendly fireproof board ... widely used in construction and decoration. It's made from magnesium oxide, magnesium chloride, fiberglass mesh, sawdust, perlite etc ... combustible perlite as filling materials.Specifications:Raw Materials: Magnesium oxide, magnesium chloride, perlite, fiber glass mesh, wood ...