This windows are fire resistant, heat insulation, sound insulation; practical, aesthetic and affordable; widely used Product type: Class A, B, C. Fire resistant time: 72min, 54min, 36min.Property:Fire resistant, heat insulation, sound insulation;Pass the GB/T 12513-2006 and the GB 16809-1997;Practical, aesthetic and affordable; Can be used in all countries and regions; fire glazing fixed windows