A data communications cable is disclosed herein. The data communications cable includes a plurality of twisted pairs of conductive wires and a separator between the plurality of twisted pairs of conductive wires. The separator includes an inner member and an outer layer being supported and shaped by the inner member for completely encapsulating at least one gas pocket between the outer layer and the inner member. The outer layer prevents the plurality of twisted pairs of conductive wires from entering the at least one gas pocket.