1.Center Pivot Roof window-RB series 2. Big ventilation. 3. Unique handle is on bottom. Center Pivot  Roof Window-RB seriesManufactured in pine,vacuum impregnated and coated with Environment-friendly lacquer.Big ventilation allow the amount of fresh air flow into the room with window closed.Unique handle for easy opening.Suitable for roofs with pitches between 150 and 900