Abstract: A sealed electrical connector comprises an electrically insulated pin housed in a receptacle and has a bared end for contact with a conductor extending partly out of the receptacle. An adjustable mechanical means is provided establishing such contact. A deformable resilient sleeve serves to seal the connection between the pin and receptacle, and access to the mechanical means is only possible through one end and along the sleeve which serves thus to seal the mechanical means.The connector is suitable for use with an implantable cardiac stimulator.