Explanatory notes
… (whether or not waxed or impregnated), varnish, enamel, pitch, oil, etc. In certain cases the insulation is obtained … co‑axial cables. (D) Sometimes a metal armouring (e.g., spiral wound steel or iron wire or strip), used mainly for … in insulating material (e.g., special alloy wire wound spirally around a core of glass fibres or asbestos) of …