Abstract: The present invention provides electrical connector assembly block apparatus comprising a pair of matable connector block parts which are provided with mutually engagable overcenter locking or latching means. The over-center locking means are comprised of at least one pair of lever arm members located on one connector block part which are pivotal about and deflectable along two orthogonal axes and are engageable with a double ramp portion on the matable connector block part to provide overcenter locking. The lever arm members are provided with means for forcibly rotating the lever arm members about the one of the two orthogonal axes which is perpendicular to the connector block to separate the end portions thereby permitting easy disengagement of the end portions with the double ramp member. The rear surface of the ramp member is provided with a shaped notch which is matable with corresponding projections of the lever arm members to provide a locked position.