Twin and earth cable comprises two individually insulated current carrying conductors and an uninsulated circuit protective conductor. Twin and Earth cable is the most common cable used for domestic wiring today.

The sheath is either grey (PVC) or white for low smoke cables (OHLS).

Also known as FTE (flat twin and earth) the live and neutral conductors are individually insulated, and the Circuit Protective Conductor (CPC) or earth, is bare. Not suitable for unprotected use outside as the outer sheath materials are vulnerable to attack by UV although protective paint can provide some UV protection.

Standard metric twin and earth cable sizes are:

Low Smoke and Fume cable (LSF), Low Smoke Zero Halogen cable (LSOH) or Zero Halogen Low Smoke cable (OHLS ) are designed to minimise the release of toxic fumes when subjected to fire or burning. In an emergency situation escape is improved by the reduced smoke and reduced toxic gasses.

A good example of standard twin and earth cable is 6242Y cable