Abstract: A connector pair with a plug (1) and a receptacle (1'), each of which comprises at least one contact insert (7, 7') in which at least one contact (9, 9') is arranged, whereby free ends (13, 13') of the housings (3, 3') can be joined in such a manner that the free end (13) of the other housing (3) projects into the open inner space (14') on the face of the one housing (3') and the contacts (9, 9') of the plug (1) and the receptacle (1') come into engagement with each other, is adapted such that in the area of the free end (13) at least one recess (17) is provided in an outer wall of the one housing (3), in the area of the free end (13') of the other housing (3') at least one engaging element (20) corresponding to the recess (18) is provided, which in a first position projects into the inner space (14') of the other housing (3') and in a second position clears the inner space (14') of the other housing (3'), and that a sleeve (30) surrounding the free end (13') is arranged, which in a rest position urges the en