the retention protrusions 65 and 70 of the harness connector 20 of fig3 therefore when the harness connector 20 is initially positioned into the initial staging position inside the module connector 25 the retention protrusions 65 and 70 engage and slide past the upper protrusions 290 and are retained in the retention gap 300 when the lever member 15 is rotated upward in the direction of arrow g fig8 about the rotational axis 27 and the harness connector 20 is pulled further downward in the direction of arrow l fig8 to connect the electrical contacts the retention protrusions 65 and 70 of the harness connector 20 of fig3 slide out of the retention gap 300 over the lower protrusions 295 to a resting position below the lower protrusions 295 the retention lower and upper protrusions 65 70 295 and 290 thus engage each other to retain the harness connector 20 in the staging position in the module connector 25 the mating post 267 includes opposed parallel side walls 305 and opposed parallel end walls 310 extending upward through an interior region of the module connector 25 the side walls 305 include the opposed u shaped catch notches 325 which are defined by flat inner walls 340 and a concave bottom wall 345.