Telephone cable 20 30 50 100 pairs Cat3 Shield Telecom Cable

Soft copper wires insulated with high-density polyethylene, foam skin, or solid insulation. Filled core, made up of groups of pairs or individual groups of pairs. Aluminum shield and outer jacket in moisture-barrier polyethylene.

Conductor
Soft copper wires
Isolation
Skin of foam or solid high-density polyethylene.
Twisted Pairs
The insulated conductors are twisted together in pairs.
Central assembly
Up to 70 pairs, groups of 10 pairs; from 100 to 300 pairs, groups of 25 pairs; from 400 pairs and more, units of 100 pairs (each unit is made up of 4 groups of 25 pairs)
spare pairs
A spare pair of white-red color in the interstices of each 100-pair unit, to guarantee the nominal number of pairs.

Category 3 data telephone cable is suitable for use in multi-line telephone systems, intercom systems, burglar alarms, speaker extensions, signaling, and power-limited circuits. The cable is for applications with temperatures up to 60°C.