Improvements in or relating to an electrical penetrator connector

An electrical penetrator connector suitable for for underwater use, with a well head; includes a fixed pin unit (2) incorporating a fixed pin (33), part of the exterior of the pin forming an electrical contact (34). A reciprocatable assembly (20) defines a bore which receives a resiliently biased slideable shuffle pin (60). A dielectric fluid chamber (41) receives part of the pin. A piston (45) applies pressure to the hydraulic fluid. Non return valves (43 fig 2, and 96 fig 3) prevent flow of dielectric fluid back to reservoir during assembly. Circuit being completed when ring (52) is adjacent with contact (34). In an alternative embodiment a screw thread and lost motion device is used to being the two halves of the connector together. The connector may contain a plurality of contacts.