u2032 14 u2033 and 13 u2032 13 u2033 are arranged in an alternating manner the contact surface 15 of the catch lugs 14 u2032 and the contact surface 27 of the cross member 25 of the clip 23 a are inclined the contact surface 15 being inclined inwardly see fig4 a secure hold is thereby ensured so that the clips 23 a cannot move to the outside under load a clip type lock or clip like connection is thus made in fig6 a a segment of a circular first spacer element 10 is shown on the inner circumference the ring shaped sealing element 11 a is located to which the wedge shaped connecting elements 103 connect radially outward with the upper wedge surfaces 104 which transition into the radial straps 118 of the drainage element 100 also provided are shortened radial straps 118 u2032 which extend inwardly from the ring shaped flow element 12 a arranged on the outer circumference of the draining spacer element 10 the radial straps 118 118 u2032 are connected to one another by circular straps 119 the graph lined sections of the circular straps 118 u2032 118 u2033 and the areas 128 that are depicted on only one strap 118 u2032 have a reduced thickness compared with the remaining.