... fix ,another can slide up and down; vertical windowsfactory 1.Material:UPVC &PVC,Aluminum ,as per your requirement;2.Colour: White ... ,fire insulated,anti-aging,anti-rust,sound insulation,corrosion-resistance;7.Environmentally friendly,Energy efficiency,Thermal insulation,good ventilation;8.UV protection---it ... :1.2mm,1.5mm,2.0mm,so on;10.Acoustical insulation:31dB;11.K-value of window:2.6w/m2.k ...