Abstract: A connector having a plug housing and a receptacle housing, each having apertured mounting projections on the end walls thereof for mounting the housings to printed circuits and motherboards, respectively, by means of a bolt and nut associated with each projections; and key means including matching planar key tabs and polygonal mounting tabs configured to nestle within a polygonal cutout on the housing projections, these mounting tabs being apertured to receive a mounting bolts so that the keys are secured to the housings and do not protrude beyond the side walls of the housings.