Roof window unit and vehicle with such a unit

The skylight unit (10) has a vehicle disc (20) that is horizontally arranged in roof region of vehicle (8). A roller blind unit is provided with guide rails (40) that are aligned in vehicle longitudinal direction and flexible sheet (34) is provided in side regions by guide rail. Guide rails are arranged directly or indirectly in front end region or rear end region by fastening device (42) over the vehicle disc. The fastening of guide rail with respect to vehicle disc is performed in discrete relative position along vertical transverse direction (2).