Abstract: A low voltage electrical system uses a main comprising an extruded insulator with a pair of channels locating metal conductors which can be installed in the channels by passing them laterally through continuously extending slots opening to a face of the extrusion from the channels. Branch conductors with plugs on their ends can be engaged in contact with the conductors by pushing their prongs through the same slots. Resilience of the extruded insulator possibly aided by deformation of the cross section in installation ensures that the slots remain closed between plugs.