In order to securely lock a male component in a female housing, a slidable member is provided on the male component and can be slid into a position wherein flexible arms on which a lock pawl or pawls are provided cannot flex to the degree that the pawls can disengage from the female housing. To reduce the overall height of the female housing, a rib is provided which extends into the mouth of the female housing and which is receivable in a slot formed in the leading edge of the male component. To shut out electromagnetic noise, metallic cover members are formed on the female housing and male component and arranged to electrically contact one another when the male component is inserted into the female housing. The metallic cover on the female housing is grounded.
