PVC windows 1.Sound and Heat Insulation 2.Resistant to the erosion of acid, alkali, salt 3.nonflammable 2011 new style PVC windows1 ... , 5mm,6mm,8mm, etc.Reinforcement steelU form galvanized steel; 1.2mm, 1.5mm, 2.0mm, 2.5mmSealRubber sealing strip, black or grey ...