Seal system for a window arrangement including manufacturing method

The disc unit has a frame (11) that surrounds the side edge of a main disc (12), which comprises a primary component which is formed as hard component and a secondary component which is formed as soft component. The strength of the primary component is greater than that of the secondary component. A guide bar (15) is arranged between main disc and auxiliary disc (14) in longitudinal direction. A window guide (35) for slidable movement of the auxiliary disc, is provided in the guide bar. An independent claim is included for manufacturing method of disc unit.