An electrical cable and a method for manufacturing the electrical cable are provided in which a plurality of insulated conductors have an inner protective layer extruded thereabout. A plurality of longitudinally extending ribs or fins or exterior ribbed or finned surfaces are formed outward of the inner protective layer between which exist a plurality of voids. An outer insulation layer can be formed in the same operation as the fins or ribbed surface and the inner layer or in a subsequent operation. A self-sealing elastomeric material is applied to the conductor surface or is present between the fins and between the inner protective layer and the outer insulation layer.