Abstract: An electrical socket connector in which individual contact members are located and retained on pegs projecting from a body member of electrically insulating material, the contact members being arranged for insulation displacement electrical connection at one end to insulated wires of two different thicknesses, and having means to set the gap between contact-making cantilever springs for co-operation with an associated plug connector. Outer covers may be latched to the body member, and the body member or one of said covers may allow access to said contact members for test probes.