Compact HD with Screw Locks These FCI D-Subminiature High-Density connectors are suitable for applications requiring robust and reliable connectors such as Telecommunications, Data, Consumer, Industrial, Military, Instrumentation and Medical markets. The High-Density range gives Input - Output interconnects to meet all design requirements and addresses the increasing needs for high density packaging. These HD D-Sub connectors have UNC 4-40 Screw locks with Board locks.