... .Chambers: 3, 4, 5, 6, 4.Thikness:2.5MM Plastic sliding windows/doors ; excellent quality;energy efficient&safety; acoustical insulation. 1 ... thickness: single, double, tripled 5mm, 6mm, 8mm; Space: 6, 9, 12, 16mm.4. Reinforcement: galvanized steel; thickness: 1.2mm, 1.5mm ... of origin: Guangzhou City, GuangDong Province, China. European style pvc sliding window