The purpose of rooflight GVK is to provide light and ventilation in the uninhabited attic. Furthermore, GVK is suitable as craftsman's roof access. This is a double glazed window with standard glazing and has a uValue of 5.1. Our rooflights are designed for in such a way that you have the opportunity to bring light into uninhabitated spaces. It is not advisable to use this rooflight in habitable rooms because of their thermal performance. The window comes with an insulating glass unit. Window frame and flashing come with a weather-resistant black polyurethane coating. The sash is made of extruded aluminium. A left-side handle comes standard, but can be moved to the right prior to installation (opening to an angle of 90.) Patented safety opening restrictor prevents the window from swinging open and hitting the roof. Integrated universal flashings for both flat and profiled roofing material up to 6cm high*. Properties  10 year guarantee on windows and flashings. Suitable for roof pitches between 20 and 65. *Not for use with standing seam metal roofs.