... density 1100-1300 kg/m3, fireproof rate B1 ISO certificate 1.FeatureMagnesium Plain Board (usually called magnesium oxide board ) is combined system of Mgo ... has the features of light quality, strong intensity, little contraction, easy constructing. Especially the unique waterproof, fireproof, corrosion proof, heat ... size : 1220*2440mm ,with the thickness of 3-20mm Magnesium fireproof board