Products in this family are components of D-subminiature style connectors, into which electrical contacts that have been applied to discrete wires can be inserted. So-named in reference to the shape of their mating end and their relatively high interconnect density at the time of introduction, an additional component known as a backshell is needed to form a connector assembly. Note that similar products assembled by means of soldering discrete wires in place are available though grouped separately, alongside similar items intended for mounting directly to a printed circuit board.