3in1 GGLS roof window is centre-pivoted and has 3 sashes in one frame, where the centre sash is fixed. Both wing sashes are operated with a full-width control bar on the ventilation flap of the top sash. The ventilation flap allows fresh air to enter the room through a dust and insect filter. Frame and sash made of laminated pine wood and ventilation flap made of pine wood are all finished with triple coat. The exterior of the frame and sash is metal-clad and therefore maintenance-free. The window is equipped with an insulating glass unit.