Coupling

coupling. The present invention relates to a coupling for a housing part (1) and a fastening part (10) have a locking arrangement (15, 16, 17), wherein elements (15, 16, 17) provision locking executed on the housing (1) and on the attachment (10), the recess not regularly inserted in the housing part (1) are so engaged with each other than the part fixing (10) starting from the extracted position is prevented from moving to the inserted position. the arms (11, 12) are so executed that, when the arrangement of the retaining ring in the arm region (11, 12) is released, the engagement between the elements (15, 16, 17) of the locking arrangement, and the attachment portion (10) by engagement of the retention ring behind the retaining segment is movable into the inserted position. this assembly with a reliable identification is obtained.