Abstract: The invention relates to an electrical supply system for electrical lighting installations and the like. The system comprises a track having an elongate insulating member housing first and second conductors extending longitudinally in spaced apart relationship and a plurality of like connectors each having attachment means operable to attach the connector to the track at a continuously adjustable position along its length and contact means making electrical contact with the track when so attached. Each connector is selectively attachable in either a first or a second orientation relative to the track such that the contact means makes electrical contact with only the first or second conductor respectively. Such an arrangement allows the connectors to be of simple construction and can be used with any number of different electrical loads.