D-subminiature connectors are so named in reference to the shape of the outer shroud surrounding the contacts at their mating end, which resembles the letter 'D', and because at the time of their introduction the interconnect density they offered was among the highest available. Products in this family are finished-goods cable assemblies with connectors applied, though products with a single connector applied are included. Due to use precedents established over many decades of service, there are significant variations in the actual connectivity provided by various cables; use care to select a product suitable for the intended purpose.