... kg/m3, fireproof rate B1 ISO certificate 1.FeatureMagnesium Plain Board (usually called magnesium oxide board ) is combined system of Mgo, ... strong intensity, little contraction, easy constructing. Especially the unique waterproof, fireproof, corrosion proof, heat preservation and protection, Sound sbsorb, mailnly applied ... size : 1220*2440mm ,with the thickness of 3-20mm Magnesium fireproof board