We only use the Velux © Brand for our Skylight windows. Our standard specification assumes SK06 GGL, these are larger frame windows to allow greater light into the space. The Velux range of windows also includes several special features. The units are double-glazed and have a unique vent/control bar, which can be set to provide fresh air even when the window is closed. The window is hinged to allow the window to be rotated 180 degrees, for cleaning purposes. The windows have a maintenance-free exterior and finished in white internally.