A male connector connects with a female connector to establish an electrical connection. The male and female connectors each include a connector housing having hold-down tabs at opposite ends thereof for securing the connector housing to a substrate. The hold-down tabs are staggered or diagonally located such that one hold-down tab is proximal a first side of the connector housing and the other hold-down is proximal a second side of the connector housing. The staggered or diagonally-located hold-down tabs stabilize the connector housing against rocking or other movement on the substrate. The arrangement of hold-down tabs also permits the connector housing to nest or merge with another similarly-designed connector housing. The nested or merged connector housing conserve substrate space and permit a higher density of contacts in a given space on the substrate, whether the space is at an edge or in an interior of the substrate. The male and female connector housings include side walls having complementary polarization features. The polarization features on the female connector housing may be formed on a detachable polarization cap. A side of the male connector housing includes a stop member for providing a positive stop for the female connector and to prevent rocking. The stop member is configured to permit side-to-side nesting of male connector housings.