Telephone cables with polyethylene insulation, in

1 Conducting cores - single-wire from copper soft wire. 2 Insulation - solid from insulating polyethylene. 3 Pairs - twisted from insulated cores of different colours.

Pairs are twisted in five or ten-pair elementary bundles. 4 Core - twisted from elementary bundles of different colours. 5 Belt insulation - polyethylene terephthalate film, overlapped, polypropylene uniaxially oriented film, overlapped.

6 Shield - aluminium-polyethylene tape laid lengthwise. A tinned copper wire is laid longitudinally under the screen. 7 Sheath - polyethylene; 8 Protective cover - of two tapes of crepe paper applied with overlapping, layer of bitumen, two steel tapes applied with a gap, layer of bitumen, glass yarn, layer of bitumen, paraffin, chalk cover.