<p>A coupling sleeve (4) has smaller outside diameter (d) than graduated circle diameter (D) reduced by the diameter of through holes (12) of connecting flanges (5). Sleeve sections (8) have side wall disks (10) adjacent to associated ring-disk like membranes (3) through peripheral wall (11). Coaxial engagement openings (13) for fastening screws (14) are provided at wall disks for through holes of connecting flanges. The coupling sleeve made of fiber reinforced plastic and connecting two face-side membranes includes the two sleeve sections screwed together via the connecting flanges projecting radially outward. The connecting flanges with through holes for fastening screws are formed in the inner peripheral regions of the ring-disk like membranes. The through holes are arranged along a graduated circle.</p>
